The England international picked up the problem during Monday night's derby match against Manchester City, and will miss the trip to Stoke, along with fixtures against West Ham and former club Aston Villa.
And Sir Alex Ferguson confirmed that the Manchester United winger will miss the next two weeks at a press conference earlier today.
"Ashley is out," Ferguson said in the Manchester Evening News. "He took a whack on his ankle. He will maybe miss two weeks."
But there's good news for Manchester United fans as well, as Ferguson thinks Nemanja Vidic will return to training today after recovering from a calf complaint.
Jonny Evans should also be fit to face Stoke this weekend after overcoming a hamstring strain that forced him to miss the last two United fixtures.
Paul Scholes should make his training ground return next Monday following a knee injury. The 38-year-old has been on the sidelines since January 26 with the problem.
Ferguson said: "It will be a terrific boost to get his football intelligence back in the squad. He has been out for a few weeks so we need to get him back out training with us."
United will be hoping to bounce back quickly from their derby day defeat to City, and face a Stoke side in poor form - they've not won in the league since February 9.