Arjen Robben is struggling to make Bayern Munich's Champions League clash with Manchester United.

He was limping badly after pulling a calf muscle while running for a pass in the 86th minute of a defeat to Stuttgart that has also damaged Bayern's hopes of the Bundesliga title.

The Holland winger spent the remaining few minutes standing forlornly on the touchline after his appeals to come off were met with deaf ears by hard-line manager Louis van Gaal, who had already used his three substitutions.

A concerned Van Gaal said: "We don't know how bad it is - the doctor needs to have a proper look but we hope it may just be a tightening of the muscle. Certainly, Robben is a hard player for us to replace so we will be crossing our fingers."