Sir David Jason said he never expected to come back to Only Fools and Horses.
The actor plays Del Boy in the popular British comedy - which has a special sketch for Sport Relief that will air on March 21 - and thought it was "the end" of the show when John Sullivan died in April 2011.
Speaking on 'The Michael McIntyre Chat Show', David explained: "As you know, unfortunately, bless him, John Sullivan, the creator of it all, very unfortunately died.
"And as Nick Lyndhurst used to say, Sullivan made the ammunition and we just fired it. So, he was the brains behind the whole thing. So when dear John died, we thought that was the end of it."
Retried footballer David Beckham came up with the idea of making a cameo appearance in the sketch, which also stars Nicholas Lyndhurst as Rodney Trotter.
The 74-year-old actor explained: "He said he had always loved 'Only Fools and Horses' and that it would be great to do something with me and Nick. So then the grapevine started to work as these things do."
David was captured by script and insists it all "came back" to him instantly and he didn't "even have to think about it".
He added: "Once I read the script that they intended to do, and I said yes I would do it, it was so much of Sullivan and so much of 'Only Fools and Horses' the original, that I said, 'Yes, let's do it'.
"When I got together with Nick for the first run-through it came back like that [clicks fingers]. I didn't even have to think about it.
"It's like anything, it's like falling off a log. As soon as I put on the gear and started to look at the script, back it came."
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