Manchester United's Ryan Giggs could be out for three weeks after limping off with a hamstring injury during Wednesday's 3-2 win against Celtic.
Giggs won United their penalty - then left the field
The Wales winger picked up the knock after he was fouled by keeper Artur Boruc, that consequently resulted in a penalty which Louis Saha converted.
But United boss Sir Alex Ferguson says Giggs should not face a longer lay-off.
"It is the first time he has suffered that injury in his right leg so we hope it won't take long to heal," he said.
Giggs will still miss United's Premiership games with Reading and Newcastle and their Champions League clash with Benfica before he will be close to a return.
And Ferguson added on Manchester United Radio: "It was absolute agony to lose him.
"He has been the leader of the team in many ways. To lose him so early is a blow to us. His form has been absolutely outstanding."
Giggs' team-mate Park Ji-sung will have ankle surgery and will be out for three months.
Meanwhile, Ferguson lavished praise on fit-again Ole Gunnar Solskjaer after his Champions League winner against Celtic.
We could have scored a lot of goals
United boss Sir Alex Ferguson
Ferguson said: "If he's on the park for 45 minutes he will get you a goal. It was a pure goalscorer's goal.
"He did what he was best at - using his brain in the penalty area. He knows where the ball's going to land before anyone else. It's a fantastic quality."
Ferguson praised Celtic's positive approach, but admitted his side could have won by a bigger margin.
He said: "We could have scored a lot of goals, but great credit to Celtic. Many teams come here and shore things up at the back and hope to steal something near the end.
"They came and had a go, which is typical of their club and which will please them, but some of our attacking play was very good.
"I've told the players that when you are in Europe you have to show your quality - we did that and I'm very pleased about that."
Celtic took the lead when Jan Vennegoor of Hesselink overpowered Rio Ferdinand and Ferguson said: "If the concentration is not good it can cause you problems and their first goal was a lapse of concentration."
Wayne Rooney was substituted late on, and Ferguson added: "It was his first game back and he needs games.
"He has only played against Porto in pre-season and against Fulham, so it is only his third game and it showed. His touch and his timing was not always Wayne Rooney."