"It's a little bit different but I had a chat with Kevin (Muscat) and Robbie (Ryan) and they think it went okay.
"The best player I've marked so far was Michael Tonge at Sheffield United, so Ryan Giggs will be a bit of a step up for me.
"I'm a little bit scared but there's no point crying about it. I would rather be there than not. I will do my best, and that's all I can really do."
Elliott is too diffident a character to be overly affected by his sudden elevation and is adamant that the brief taste of fame will not go to his head. After all, he began the season in Millwall's youth team after two years spent cleaning Marc Bircham's boots.
"Playing in an FA Cup final is a dream come true. We're the underdogs and just getting to there is a great achievement," he said. "But I'm not going to change and won't get big-headed all of a sudden.
"It's still the same Marvin. It's not as if I've been going down Wandsworth High Street shouting, 'I'm playing in the Cup Final!'"
While Elliott's Millwall career is just taking off, his fellow full-back in the final is preparing to leave The Den after six years' service.
Ryan, the 27-year-old left-back, will play his last game for the club at Cardiff after rejecting the offer of a new one-year contract. And he is, of course, hoping to bow out on a high.
But he has turned his back on the prospect of European football and a potential promotion-campaign because of his determination to secure a longer contract elsewhere.
Offers, though, have not been flooding in and so the final represents a wonderful opportunity to show what he can do.
He said: "It'll be my last game for the club and what a way to go out with an FA Cup Final, and hopefully with a winner's medal.
"It's a massive game and could put me in the shop window. I'm not sure where I'll be in August and I've had no offers.
"I've had six great years here but wasn't happy with the contract I was offered so unfortunately it's time to move on. If I have a good game who knows what can happen?
"You never say never in football and I'd love to stay at Millwall. If I play well in the final they might come back to me with a twoyear deal. It's a brave move I suppose and football is a dangerous world, but I'm prepared to take the risk.
" I thought about the prospect of European football and a promotion campaign but I've got to look after myself.
"I don't see myself getting a two or three-year contract at
Millwall and if I can't get a club now then I won't get one in 12 months. I may as well move on now."
Ryan could hardly face a tougher examination than the silky dribbling skills of Cristiano
Ronaldo. United's wing wizards present their greatest attacking threat and the honest
Irishman makes no attempt to disguise his rather basic game plan.
Ryan said: " Giggs and
Ronaldo are their main attacking players so I'll be tucking in three or four midfielders-with me. I'm aiming to kick them all over the place and I haven't got a plan B. I'll be tucking Livers (David Livermore) and (Peter) Sweeney in and we'll see what happens.
"Ronaldo is a special player and marking him will definitely be the biggest challenge of my career. He's been on fire the last few weeks and I don't know how to slow him down - my only conclusion is that I have to kick him!
"United are a special team but anything can happen and we'll try to make life as difficult as we can for them."
Unusually for an aggressively-inclined Millwall player, the country will be cheering him on.
