Ryan Giggs will be out for at least two weeks after injuring his hamstring in Manchester United's 2-2 draw at Bolton Wanderers today.

Wayne Rooney aggravated a left ankle problem and was substituted after 61 minutes, but United believe the England striker will be fit to face Valencia in the Champions League on Wednesday.

"Wayne Rooney had a bit of a knock," said Mike Phelan, United assistant manager. "He has a little issue with his ankle.

"We don't know how serious. We will have a look in the morning but we think he will be OK for Wednesday.

"He has been playing with it for a couple of weeks now, and during the game we decided he wasn't getting into the areas we wanted and he wasn't getting chances, so we had to change it."

Giggs was substituted after 53 minutes at the Reebok Stadium and is almost certainly out of the game in Valencia and a trip to Sunderland in the Premier League next Saturday. He may also be in doubt for the league match against West Bromwich Albion at Old Trafford on 16 October.

"Of the two injuries, Ryan is the more serious, with a hamstring," the United manager, Sir Alex Ferguson, said. "He'll be out for a couple of weeks. We're looking to get Wayne ready for Wednesday."

Of United's performance, Ferguson said: "Coming from behind, twice, away from home is not easy thing to do, and we showed character. It was a fair result."