Murray gets call to play as injured Federer withdraws

Roger Federer is optimistic he will be fit for next weekend’s Davis Cup final after his dramatic withdrawal from the ATP World Tour Finals.

The world number two had been scheduled to play Novak Djokovic in a highly-anticipated climax to the tournament at London’s O2 Arena but pulled out with a back injury suffered in his epic semi-final victory over Stan Wawrinka.