Wawrinka happy to use Federer's 'SABR'

New York - Stan Wawrinka admitted Wednesday that he has no reservations about imitating his rivals' tricks of the trade, including Roger Federer's latest weapon - the 'SABR.'

Federer has recently developed a new chip-and-charge approach on second serve which has been called 'Sneak Attack By Roger' or 'SABR' for short.

Wawrinka, who will face his close friend in Friday's US Open semi-finals, used his own version of the tactic Wednesday in his 6-4, 6-4, 6-0 quarter-final win over South Africa's Kevin Anderson.

"I'm not trying to do what he's doing. Just the reason why I improve so much the past few years, it's also because I'm looking a lot what the top guys' doing, Novak, Roger, Rafa," said the 30-year-old French Open champion.

"We all see what Roger is doing right now. It's quite impressive. He's doing it against everybody. I saw him play also against Anderson in Cincinnati, and I was surprised how close he was returning.

"But it's actually a good way against Anderson to be closer than behind, because you completely cut the time from him."