Jose Mourinho has told Manchester United to be inspired by Roger Federer and ignore concerns over the pitch in their Champions League meeting with Young Boys.
Mourinho will not risk Antonio Valencia due to concerns over the Swiss side's artificial surface, with the right-back having missed the start of the Premier League season with a knee injury.
He will sit out United's Group H opener at the Stade de Suisse on Wednesday, which could hand right-back Diogo Dalot his debut for the club.
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And Mourinho opted to use an unexpected example in the form of tennis great Federer when discussing the pitch in his pre-match news conference.