Mitch Keller lost for season with teres major muscle issue in shoulder

MILWAUKEE — The Pirates’ starting rotation has remained remarkably healthy this season.

That changed Monday, as they announced Mitch Keller will be out of the season with a teres major muscle injury in his right shoulder.

Keller won’t be allowed to throw for six to eight weeks, preventing a possible return. The teres major is one of the major muscles controlling the shoulder joint,…