Manchester United manager Jose Mourinho has spoken out about why he had to substitute Marcus Rashford during the Red Devils 1-0 Champions League victory against Benfica at the Estadio du Luz on Wednesday.

This proved to be a difficult encounter for United in Portugal and they were allowed to win after Rasford managed to break the deadlock in the second half following an error from young Benfica goalkeeper Mile Silvar.

Mourinho has now revealed why he had to take off Rashford and added that he did this as he saw that the player was in pain.

He said: "I thought it was cramp. I asked him and he told me 'no'.

"He felt something in his knee. Hopefully it's not a big one."

The loss sees United maintain their 100% win record in Champions League group A. Mourinho's men currently have three wins out of their three games played thus far and lead second placed FC Basel by three points.