Rooney came off the bench and secured a 2-1 win to United over Aston Villa in the Carling Cup final on Sunday.
United boss Sir Alex Ferguson has confirmed that the 24-year-old suffered a knee problem in the game.
“He got a whack right away,” said Ferguson.
“He has been complaining a little about that for a few weeks and was holding it a bit today.
“In fact, I thought we might have to take him off but he wanted to stay on so it was good.
“The doctors are assessing it and I don’t know what England are going to do.”