Roger Lloyd-Pack was originally scripted into the new 'Only Fools and Horses' sketch.
The late Trigger actor - who passed away in January following a battle with pancreatic cancer - had expressed his desire to star in the charity special with Sir David Jason, Nicholas Lyndhurst and football legend David Beckham before his untimely passing.
The new sketch was written by Jim and Dan Sullivan, the sons of show creator John Sullivan, who passed away in 2011.
Jim said: "It has been emotional, and dad was never far from our thoughts during the whole process.
"And, of course, we were all shocked and saddened at the news of Roger Lloyd Pack's death. We had originally written Trigger into the sketch and Roger was supportive of the whole thing.
"We had heard he had been unwell but had no idea how serious it was. It wasn't until shortly before filming that we heard he was too poorly to perform, such was eagerness to be involved - a true testament to his character."
The Sport Relief sketch was conceived when David, 38, approached the brothers about doing a charity special and the duo were taken aback by what a big fan the retired football player is of the sitcom.
Jim told Radio Times magazine: "We had no idea and it was lovely to meet him and hear him talk about his favourite episodes and scenes, and how his son, Brooklyn, is now also a fan."

Joan Collins has recreated Ellen DeGeneres' Oscars 'selfie'.
The 80-year-old actress gathered a group of British celebrities, including Sir Ben Kingsley and Jeremy Irons, together at the Prince's Trust and Samsung Celebrate Success Awards in London yesterday (12.03.14) to recreate the famous snapshot, taken by Bradley Cooper on the talk-show host's phone at the Oscars ceremony earlier this month.
The 'Dynasty' actress managed to encourage a number of the other guests at the awards to get involved and the result was a rather blurry photograph of Joan, Ben and Jeremy joined by Pixie Lott, Vernon Kay, Jools Holland, Dominic West and Luke Evans.
Meanwhile Vernon Kay's wife Tess Daly, sports broadcaster Gabby Logan, 'X Factor' winner Sam Bailey and presenter Phillip Schofield missed out on being involved in the British version as Joan's arms couldn't stretch as far as the 'American Hustle' stars did.
Posing together at the 86th Academy Awards at the Dolby Theater in Los Angeles for the original 'selfie' were Ellen, - who was hosting the ceremony - Bradley, Julia Roberts, Jennifer Lawrence, Meryl Streep, Brad Pitt, Angelina Jolie, Kevin Spacey, Channing Tatum, '12 Years a Slave 'star Lupita Nyong'o and Jared Leto, who was unfortunately squeezed out of the shot.
Joan has since posted her "selfie support" on Twitter in a bid to receive more retweets than Ellen's image - which broke records with over 3.2 million people retweeting the star studded photo - but so far it's only been re-posted by under three hundred social-media users.

Rihanna and Drake were spotted holding hands after his concert in Manchester on Tuesday night (11.03.14).
The 'What Now' singer, 26, and the 24-year-old rapper are rumoured to have gotten back together and they now appear to have confirmed their relationship after they were seen holding hands as they made their way to the after-party at Club Entourage.
Following the party the couple are said to have continued their night out together by renting out an entire bowling alley where they stayed until four o'clock the next morning, according to TMZ.com.
This isn't the pair's first date since reportedly rekindling their romance however, as they were also seen getting hot and steamy at London's celebrity hotspot Cirque Le Soir on Monday night (10.03.14) and appeared to have enjoyed a romantic meal together on Sunday (09.03.14) as they were photographed leaving the Nobu restaurant in Mayfair.
Speaking about the music stars' night at Cirque Le Soir, a source said: "There's definitely no question about their romance anymore. Rihanna and Drake spent the whole night with their tongues down each other's throats and didn't seem to care about everybody seeing."

Karen Gillan found it "scary" when she first saw herself as Guardians of the Galaxy's Nebula.
The 26-year-old actress - who shaved her head for the part - will play the female villain in Marvel's big-budget superhero film, where she dons purple face paint and a black face-piece.
Gillan could believe what she was seeing when she saw herself in the mirror, dressed in character, for the first time.
Talking to collider.com: "I couldn't believe it. I was like 'woah'. I'd seen mock up pictures and they'd done make-up tests on other people, so I had an idea. But, when I saw it on myself it was really scary."
The make-up and costume helped Gillan get into character since she didn't feel like she was herself.
She added: "It did half the job for me. I mean, having shaved my head and working out so much, I just felt like a different person so that really helped with the performance."
She will star alongside Chris Pratt who will play the lead role of Peter Quill - otherwise known as the Star-Lord.

Skrillex wanted his debut album to be "crazy".
The dubstep producer, real name Sonny Moore, kept details of his record 'Recess' a secret before streaming it in full on his Alien Ride app on Tuesday night (11.02.13) ahead of the official release on March 18.
Skrillex told Rolling Stone magazine the process was about: "Taking my sound and expanding on it, but being more playful, taking it to different places."
The record features a number of cameos, including Chance the Rapper, Diplo and Kid Harpoon and Skrillex insists he has worked hard to make the album cohesive.
He explained: "I call my songs vibescapes ... There's always a foundation under the tracks that you can feel and pick up on. An emotion. There's a lot of organic samples ... wind, breaths, clocks cut into tiny pieces.
"I never made pure club music early on. All the first Skrillex releases were hard to mix into."
He added: "I wanted to make a crazy record [but] I wanted to stay true to who Skrillex is."
Talking about the mysterious app, which was nothing more than a game with a countdown clock, Tim Smith, his longtime manager, said: "That signals that something's coming, but no one knows what it is."
Skrillex, 26, admits he'll probably make less money sreaming his album through the app first but it was "more about the fans."

Neil Patrick Harris "loves being scared".
The 'How I Met Your Mother' actor enjoys being frightened and taking part in daring stunts and thinks that's why he always enjoyed hosting the Tony awards.
The 40-year-old star said: "I love being scared, walking through a field of maize in October with people jumping out and frightening me.
"I know they can't touch me and I like the experience of it -- weirdly, I think hosting the Tony Awards is almost the same thing. I'm out there, it's live, something could go terribly wrong, but we have lots of outs and I have a teleprompter and we've already rehearsed everything. It's fun and a bit dangerous, but I know I'm going to be all right."
The actor, who hosted the ceremony four times before passing on the baton to actor Hugh Jackman this year, is baffled by stars who can't read an autocue.
He told OUT magazine: "It always amazes me when Oscar-nominated actors go on award shows and read the teleprompter as if they have never seen it before.
"And I know they've already vetted it, that their publicist or manager has already agreed to it, and yet, there they are, standing there, with that kind of 'Who wrote this s**t?' attitude while monotonically reading off these words."
The star, who will appear as womaniser Barney Stinson in 'How I Met Your Mother' for the last time this month as the Fox show comes to an end, is sad he's leaving the character behind but looking forward to new challenges.
He said: "I won't ever be able to play someone like Barney again because he's so unique, but we had over 200 episodes ... And my exclusivity deal is done with Fox."
He jokingly added: "So finally I'll be able to do more porn."

Dominic Cooper hates fancy dress parties.
The 'Need for Speed' actor favours casual clothes when he isn't working and hates socialising at parties where he has to dress up as a character because it reminds him too much of his work.
He said: "I love anything vintage, a good quality suit, scruffy jeans and my trusty leather army boots. I like being casual. As an actor, I'm in costume all the time. That's why fancy dress parties are my idea of hell."
The 35-year-old star is an avid follower of fashion and takes a particular interest in emerging designers.
He said: "I can't believe how easily fads come back into style, like skinny jeans. But I've always loved fashion.
"It influences generations and resonates with a moment in time. I love seeing what designers come up with, especially young designers. I think they're artists."
And Dominic can also remember splashing out on his first-ever new suit to mark his appearance in stage show 'The History Boys'.
He told Britain's InStyle magazine: "When I got paid for doing 'The History Boys' in New York, I bought a nice suit. No idea who by, but it was a big moment as, before that, I'd only worn hand-me-downs with baggy kneecaps. I certainly didn't have the money to buy suits when I was a teenager."

Lauren Conrad has regular date nights with her fiancé.
The former 'The Hills' star has been dating her beau William Tell for just over two years and she believes the key to a successful relationship is making time for each other.
She said: "It's just like any other couple with full-time jobs. You make date night and you have weekends, hopefully. Not [all] weekends, but some weekends. I'm really fortunate in that I get to do things that I love, so it doesn't feel like work. I think if you're doing something you love, it's not a lot. You're excited every day.
"We haven't been to a club together in a very, very long time, if ever," Conrad said. "We probably entertain more than we go out, to be honest. I love just having a couple of people over for dinner. It's easier for me. I don't have to wear shoes. Everybody's happy."
Meanwhile, the 28-year-old star, who got engaged to William, 33, in October last year, previously said she wasn't in a rush to tie the knot, but admitted last month that she's chosen her wedding dress.
She said earlier this year: "You have the rest of your life to be married. Enjoy falling in love. When girls get caught up in the timeline, it becomes more about the wedding than the marriage. You should be with someone with whom you could elope this weekend and be happy."

Angie Everhart underwent surgery on her neck yesterday (11.03.14).
The former Sports Illustrated model - who has dated Sylvester Stallone in the past and was engaged to Joe Pesci - had to have an operation on a herniated disc after suffering from nerve pain.
She took to Twitter after the surgery, writing: "I'm out of surgery- it went well- had floating pieces of disc on my nerve. All gone! Staying in hospital another night for pain management (sic)."
However, earlier that day, the 44-year-old actress appeared to be fed up of visiting medical centres after being hospitalised earlier this month due to the trapped nerve.
She tweeted: "Sitting in the hospital waiting for my surgery. Oh boy. Too many surgeries lately. No fun. Feel like I was just here. (sic)".
It is believed the flame-haired beauty damaged her nerve after crossing her legs too long, according to the Express newspaper.
Meanwhile, Angie was diagnosed with thyroid cancer in May last year and had surgery shortly after.
A representative for Angie said at the time: "[Angie] wants to set the record straight by letting everyone know that it is true that she has been diagnosed with thyroid cancer, however, the prognosis is very good."
Angie is now free from the condition and is on a mission to help raise awareness of thyroid cancer.

Aaron Paul admits being married to his wife is "incredible".
The 'Breaking Bad' star and his beau Lauren Parsekian tied the knot in a carnival-themed wedding in Malibu last May, after two years of dating, and he insists he loves her more and more every day.
He said: "I fall more in love with her every day. Being married to my wife is incredible."
The 34-year-old actor isn't afraid to tell the model how much he cares about her either because he believes it's important she knows how much he appreciates her.
He explained to People magazine: "I tell her every day that I love her. I've got to. If you marry someone, you have to let her know how much you care and I do that as often as I possibly can. She really is the best wife and she should know that."
Meanwhile, Aaron isn't just an affectionate husband as he also likes to help out around the house.
He said: "I like to clean the house. I pick up after myself and will vacuum. I do it all."

Elizabeth Olsen is engaged.
The 25-year-old actress and her boyfriend Boyd Holbrook are set to tie the knot after the 32-year-old star popped the question following two years of dating, according to Us Magazine.
A source said: "They've been by each other for a while, taking a lot of couple time."
The pair first met on the set of 'Very Good Girls' back in 2012 and have been inseparable ever since.
The loved-up duo took their relationship to the next level a few months back when they reportedly moved in together in Brooklyn, New York City.
The source explained: "They moved into a place in Brooklyn a few months ago."
Meanwhile, the Olsen family seem to be keen to head for the aisle as Elizabeth's older sister Mary-Kate, 27, also got engaged to her boyfriend Olivier Sarkozy, 44, just two weeks ago.
The fashionista is yet to confirm reports that the French banker proposed to her, but she has fuelled rumours recently by flaunting a diamond sparkler on her ring finger.
Mary-Kate and Olivier, who have been dating for two years, reside in New York, where they have a $6.25 million townhouse, but their union has caused some controversy due to their 17-year age gap.
Mary-Kate's twin sister Ashley is also dating an older man, with it recently confirmed she is seeing 47-year-old 'Moneyball' director Bennett Miller.

Beyoncé took her daughter to Dublin zoo yesterday (11.03.14).
The 'XO' hitmaker is currently in the Irish capital for her 'Mrs. Carter World Tour', but she took a break from her hectic schedule to spend the day looking at animals with two-year-old Blue Ivy.
The 32-year-old singer took to her Instagram account today (12.03.14) to post a picture of her cradling the toddler while they both gazed at a group of giraffes in the distance.
The blonde beauty attempted to keep a low profile by wrapping both her and Blue in woolly hats, but managed to draw attention to herself by wearing a black bomber jacket with 'Mrs. Carter World Tour' emblazoned across the back.
Beyoncé and Blue's trip to the zoo follows their outing to the local Phoenix Park the day before, where they spent half an hour in the playground with Jay Z.
The rapper, 44, and Beyoncé, along with their security team, then enjoyed dinner at fashionable eatery Coppinger Row.
It seems the pair have been enjoying the culinary delights of the city, as following the 'Drunk in Love' hitmaker's show on Sunday (09.03.14), the "extremely humble" couple dined at upmarket eatery Fade Street Social, which opened late just for them.
A representative said previously: "Usually the kitchen is closing around then but we held on for a few minutes to accommodate them. They were extremely nice and friendly and left very happy."