Becker slams 'disrespectful' Federer over 'SABR' tactic

German tennis legend Boris Becker has criticised Roger Federer for 'disrespecting' opponents with his new 'sneak-attack' strategy.

The Swiss maestro used the tactic, which involves advancing right up to the service line on an opponent's serve, predominantly at the US Open in a bid to end his three-year Grand Slam drought at Flushing Meadows.

Dubbed as the SABR--Sneak Attack By Roger, the purpose of the move is to disrupt opponent's rhythm and force them into making an error.

However, Becker, who is currently coaching top seed Novak Djokovic, described the move as 'almost disrespectful' to opponents and said that the players of his generation would not have accepted it, adding that they would have instead gone straight at Federer, News.com.au reported.

The 17-time Grand Slam champion set up an all-Swiss semi-final clash against compatriot Stan Wawrinka after cruising past Richard Gasquet 6-3, 6-3, 6-1 on Wednesday.