The United centre-back has recovered from a back injury and will return to the squad for the top-of-the-table clash against Chelsea at Old Trafford on Sunday.
"Rio's fit to play," United manager Sir Alex Ferguson has said.
"He's missed the last few games, and that's given us time to get things settled down.
"He's one of the best centre-backs in the world, and he does make a difference because he's got the presence to play in these big games."
Patrice Evra is also available for selection having now completed a four match suspension.