United manager Sir Alex Ferguson will consider playing the 21-year-old Brazilian in the reserves against Everton on Thursday.
Rafael has been out since August, when he had surgery on a shoulder injury.
Ferguson said: "Rafael has been training for over a week. It was a big operation on his shoulder and we hope we can maybe fit a game in for him - maybe the next reserve game.
"He's coming along fine, there has been no setback and he has been training every day."
Rafael's return could prove timely, with Chris Smalling having been ruled out for a month with a fractured foot.