Wayne Rooney will miss Manchester United's next two matches, according to manager Sir Alex Ferguson, who believes he will be 'out for more than a week'.
The England striker was forced to sit out the trip to Stoke after suffering a hamstring injury in training on Friday.
United are in Champions League action on Tuesday, at home to Basel, before hosting Norwich City next weekend.
"It's not a serious injury but I don't think he'll be available for next week," Ferguson told MUTV.
"I think he'll be out for more than a week."
Rooney could also be doubtful for England's final Euro 2012 qualifier against Montenegro on 7 October if he misses United's only two games before Fabio Capello names his squad.
It turned out to be a costly day for the Premier League leaders, who lost Jonny Evans in the warm-up and then saw Javier Hernandez forced off after 11 minutes with a dead leg.
"Jonny Evans got an ankle injury in training yesterday," added Ferguson.
"We had a nightmare of a training session - Evans, Michael Carrick and Wayne Rooney all got injured. Jonny thought he'd be OK but in the warm-up it was no use."
The quartet join a growing injury list at Old Trafford which already includes Nemanja Vidic, Chris Smalling, Rafael da Silva, Tom Cleverley and Darron Gibson.
There was good news though for United after Rio Ferdinand and Danny Welbeck both made successful returns to action.
United were held to a 1-1 draw after Peter Crouch, who Ferguson dubbed a persistent fouler, cancelled out Nani's 27th-minute opener.
"Crouch fouls all the time, he gets huffy but he jumps on top of defenders all the time," said Ferguson.
"He has been doing that for years, referees know that. He maybe caught Phil Jones for the goal but he is a definitely a handful in the air."