The Boston Red Sox have fired pitching coach Juan Nieves.

The club has not yet announced a replacement.

Boston ranks 29th in the Major Leagues in ERA at 4.86. The starting rotation also ranks 29th, with a 5.54 ERA, and the bullpen is the only one in the majors that has thrown over 100 innings (101 1/3) this season.

Nieves, 50, was in his third season as Red Sox pitching coach, formerly pitched for the Milwaukee Brewers and came to the Red Sox after 14 seasons in the White Sox organization, the last five as Chicago's bullpen coach.