Andy Murray has admitted that it will be "tough" to combat Ivo Karlovic's serve when the two players face off in the fourth round of Wimbledon on Monday.

Karlovic has hit a tournament-high 136 aces so far at SW19, while he also boasts more points on his first serve than any other player in the opening three rounds.

Murray, who overcame Andreas Seppi in four sets to progress into the second week of Wimbledon, has never lost to Karlovic in their previous five meetings, but is wary of the weapons at the Croatian's disposal.

"Obviously he's served extremely well this tournament," Murray is quoted as saying by PA.

"The grass helps in some ways because it's not bouncing as high as it might on a hard court or a clay court. But it's mainly just the fact that he can hit so many of the angles on the court.

"He serve and volleys too. He's a very solid volleyer. You can't just pat the return back into play, you need to try to do something with it, so it's tough."

Murray also talked up his own form so far at Wimbledon, although the Scot acknowledged that there is still room for improvement.