Kevin Anderson has admitted that Stanislas Wawrinka has established himself as one of the players to beat on the ATP Tour.
Wawrinka has won two of the seven Grand Slam tournaments that have taken place since the start of 2014, while he has been a regular fixture in the top five of the world rankings.
The 29-year-old is quoted by ITV Sport as saying: "I think especially in the last few years, Stan has really put himself up there as one of the main contenders for Slams.
"I really feel he's playing some of his best tennis. To win two slams in the last year and a half is obviously a testament to that. He knows what it takes. He's been in that position. It's my first time, but I feel like I'm hitting the ball very well."
The two players have previously met on seven occasions, with Anderson prevailing in the four matches that have taken place since March 2014.