Since then, he's made a positive impression on manager Mike Scioscia, who called Guerra "one of the bright spots of this season."
In seven appearances since returning to the big leagues, Guerra has posted a 1.35 ERA and provided something that's been lacking in the Angels bullpen -- length. He's worked at least one inning in each of his outings, extending himself as far as 2 2/3 innings on June 10 against Cleveland. Guerra worked 1 2/3 scoreless innings in Saturday's 7-3 loss to the A's, allowing two hits and striking out one.
Scioscia said Guerra had made significant progress in his ability to control games before the appendectomy surgery at the end of Spring Training, and he has continued to improve in the big leagues. His pitching has come along, too.
"It seems like his stuff is starting to pick up," Scioscia said. "He throws strikes, he has a couple really good pitches that could be out pitches and he's throwing the ball well for us."
Guerra's ability to pitch multiple innings has been a reprieve for a bullpen that has often found itself overworked this season. They've posted solid numbers, with their 3.92 ERA entering Saturday being toward the middle of the pack in the Majors, but have worked the third-most innings of any AL team.
Scioscia, who found his team last in the AL West and in the midst of a five-game losing streak before Saturday's game against Oakland, said that if anything was going to turn things around, it was going to be the club's pitching. Angels starters have posted a 4.77 ERA this season, ranking 22nd in the Majors, giving the bullpen few chances to reset.
"Our bullpen needs the functionality," Scioscia said. "We need guys who can get into their roles and can get outs when you're trying to hold a lead. We think that [Guerra] can grow into that role."
• Angels setup man Joe Smith, who has been dealing with a strained left hamstring, will begin a rehab assignment on Sunday with Class A Advanced Inland Empire. Smith hasn't pitched in the Majors since June 4.
• Angels third baseman Yunel Escobar was held out of the lineup for the second consecutive game Saturday. He is listed as day to day with a tender left knee, and hasn't played since sustaining the injury during his seventh-inning at-bat Thursday against Oakland.