Federer pondering Isner serve

Roger Federer may have to rethink his hyper-aggressive strategy against the big serving John Isner when they meet at the US Open next week.

The duo are set to face off in the fourth round at Flushing Meadows on Monday. The Swiss ace has adopted a hyper-aggressive approach of late, where he comes to the net often and attacks second serves. 

However, Isner is considered one of the best servers in the game and Federer will have to think twice about rushing at a second serve.

"I don't think so," said the 34-year-old about rushing the big American's serve.

"I can always try. But it's probably not the right guy to do it against. The idea is not to use it very much against a player like that.

"I have done pretty well over the years against big servers, so, I mean, clearly I will think about it. But I don't think that's going to be the turning point of the match, to be quite honest. I need to make sure I protect my own serve first."

The 17-time grand slam winner enters the fourth round clash in New York City having yet to drop a set.

Meanwhile, Isner is looking forward to the clash against the second seed.

"It's going to be fun," quipped the 30-year-old. 

"It's what I work so hard for, to get an opportunity like this. On Monday I'm going to have fun with it. At the same time, I'm going to go out there and believe that I can win the match."

The pair have met on five previous occasions, with Isner’s lone win coming in a Davis Cup tie in 2012. Otherwise Federer has won the last two encounters in straight sets.