The Boston Red Sox are calling up 31-year-old reliever Cam Booser, who has never pitched in the major leagues and was out of professional baseball for four years.
Yamamoto's reliance on his curveball and splitter through his first four outings makes his arsenal one of the most unique in MLB.
Chapman signed a $10.5 million deal with the Pirates this past offseason.
The Cubs announced the team activated starter Jameson Taillon from the 15-day injured list and Patrick Wisdom from the 10-day injured list on Thursday. In a reciprocating move, the Cubs optioned Hayden Wesneski and Miles Mastrobuoni to Triple-A Iowa. Taillon has yet to pitch this season since dealing with back strains that kept him on the injured list. He recently...