Roger Federer pulls out of ATP World Tour Final versus Novak Djokovic, owing to back injury

Swiss maestro, Roger Federer has confirmed that he will not play  Sunday's ATP World Tour Final against Novak Djokovic, owing to a back injury.

Federer issued a 'public apology' at the O2 Arena, and also cited 'lack of match fitness' as the reason for his abrupt withdrawal.

Earlier, the Swiss ace had edged out fellow compatriot, Stanislas Wawrinka, in a close semi-final, thus raising visions of a seventh tournament win, come the final.

Now, Djokovic will instead face Andy Murray in an exhibition match, which will serve as replacement for the final.

Murray will later join John McEnroe, to play another exhibition doubles tie, against Tim Henman and Pat Cash.

Meanwhile, Federer has fresh doubts cast over his inclusion in the Davis Cup final against France, thanks to his injury concerns.