Sir Alex Ferguson has acknowleged that there's a real battle for United's right-back slot, but we want to know who you think should be playing there.
The Reds have as many as six players vying for the position, and all have their merits, according to Sir Alex: "It is a really hotly contested position."
Aside from the senior professionals like Gary Neville, John O'Shea and Wes Brown who have occupied the position on a regular basis in recent years, the Reds have a number of up-and-coming defenders who can fill the roll.
"We've got five or six players who can play there," added the boss. "Rafa da Silva has got great potential to be a top player for us - as has his brother Fabio.
"We've also got Ritchie De Laet who can play there. So we're quite comfortable in that position."
Get involved with the debate by voting in our poll and posting your views on the Talking Reds thread.
Here are some of the best comments we've seen so far:
"It has to be John O'Shea - not because I'm Irish, but because I think he has been one of our best players this season and last."
Posted by Poland 86
"The boss knows best who to play and when to play them. All have their merits. We need all our defenders to be speedy whenever there is a sudden counter attack."
Posted by Man United strikers
"I'd say our long-term right-back is Rafael but he's still the raw diamond. For me, the first-team spot has to be between Nev and Sheasy. O'Shea has been one of the performers of the season while Neville's partnership with Valencia (a Beckham-style winger) has shown glimpses of greatness. The gaffer has a knack for rotating his players, so I think O'Shea and Neville will get 25+ appearances."