A few days ago, Roger Federer unveiled a new serve return to thwart his opponent’s second serve – charging to the edge of the service line and returning the serve with a half volley. Now as Federer prepares to face off against Novak Djokovic in the final of the US Open for a shot at an 18th Grand Slam, the new move has got a name – the SABR, which stands for “Sneak Attack by Roger” and is ruffling quite a few feathers.

Former tennis legend Boris Becker, who is also Novak Djokovic’s coach, fired the first salvo at Federer over his use of the SABR. The former German world number one slammed Federer’s new move, labelling it “disrespectful” and went on to say that former players would have gone “straight at” Federer if he had tried his new strategy on them.

"If he would have played a [John] McEnroe, [Jimmy] Connors, [Ivan] Lendl or even me, we would have said 'Roger, in all honesty I like you very much [but] I'll go straight at you'," said Becker.

Becker has support in the form of John McEnroe, who also admitted that he would have also found it “insulting”, if Federer had tried to use the tactic on him. Djokovic, on the other hand, kept a poker face about the issue, preferring to admit that while it was an exciting shot for Federer, it wasn’t so much on the other end of the net.

Federer, though, dismissed any suggestions of disrespect and confirmed that he meant to continue to use it in the much-awaited final. This war-of-words has certainly added spice to, what should be a fiercely-contested clash between two masters of the modern game.