Angels manager Mike Scioscia said Pineiro will work out of the bullpen while he tries to figure out the mechanical issues that have led to a 14.85 ERA and five home runs allowed in his past four starts. The Angels likely will need to find a replacement for Pineiro by their game at Yankee Stadium on Wednesday.
If Jered Weaver drops his appeal of a six-game suspension by Saturday, the Angels could get by with one additional starter added to their rotation. The primary candidates appear to be reliever Hisanori Takahashi and minor leaguers Trevor Bell and Garrett Richards, who was 12-1 with a 3.04 ERA and pitching Thursday night for Double-A Arkansas.
Statistically, the Angels have the best rotation in the American League, but they're not deep in pitching throughout the organization. It shows how badly Pineiro was struggling that the Angels decided to act so decisively. They trail the Texas Rangers by 1½ games entering Thursday's game.
"The bottom line is, where JP was right now in his game and where he's shown he can be and where we need him, that divide was widening," Scioscia said. "We need him to take a step back and hopefully move forward with it."
Pineiro is in the final year of a two-year, $16 million contract he signed before the 2010 season. He was 10-7 with a 3.84 ERA last year.
Mark Saxon covers the Angels for ESPNLosAngeles.com.