United manager Fergie confirmed: "Rio's back - and he does make the difference.
"From time to time he gets spasms in his back. He's missed the last few games so that gives us the opportunity to settle down and do some work on it.
"He's trained the last few days and is feeling much better. He is one of the best centre-backs in the world.
"His pace, balance and use of the ball have always been a feature of his game. But we've been lucky to have someone like Jonny Evans to replace him."