PITTSBURGH -- Pirates pitcher A.J. Burnett will undergo surgery on Friday to repair a fractured right orbital bone.

The right-hander was injured Wednesday at the team's spring training facilities in Bradenton, Fla., while trying to bunt. The failed attempt caromed off his bat and into his face.

He flew to Pittsburgh late Wednesday to be further evaluated.

There is no immediate timetable for Burnett's return. The 35-year-old was acquired in a three-player trade with the New York Yankees last month and was expected to join the rotation on a team looking to improve on a 72-90 record last season.