Wayne Rooney will undergo a scan on his injured knee to discover the extent of the injury.

Rooney was a surprise omission in Manchester United's XI on Tuesday against Stoke.

“It is his knee but we have to wait for tomorrow to say anything about it because you never know with a knee. In my opinion it is not so heavy but I am not a doctor,” said Louis van Gaal. “We have to wait a scan and we will know more.”