The Field of the 2013 Winston-Salem Open has beefed up as World Number 6, Tomas Berdych, has entered as a wild card.

Berdych who fell to John Isner in last year's tournament will be the one seed, with Isner taking the 3rd seed.

Andres Seppi will be the two seed due to the withdrawal of Tommy Haas. Haas has left the field because of precautionary health issues. Bernard Tomic of Australia withdrew as well.

Berdych has a little work left to do in Cincinnati before turning his attention to Winston-Salem. He faces Rafa Nadal in Saturday's semifinal of the Cincinnati Masters.

Berdych will be in a field that includes a hot John Isner, Gael Monfils, Sam Querrey, James Blake and Mardy Fish.

Qualifying is underway now at Wake Forest University.