The bullpen gave up a season-high 13 runs to the Mariners as the Angels endured their worst loss in more than four months.
"We didn't get it done on the mound," Angels manager Mike Scioscia said. "We just didn't pass the baton like we have been all year. These bullpen days, we've gotten to a certain point in the game with a lead, we've held it and done a good job."
Despite the defeat, the Angels' magic number to clinch the American League West dropped to two with Oakland's loss to Texas. They can clinch the division Wednesday with a win and another Oakland loss.
Tuesday was the fourth bullpen game for the Angels since Richards was lost to season-ending knee surgery. In the previous three, the Angels had notched three victories while outscoring opponents, 17-8.
In Tuesday's drubbing, the Angels gave up 10 runs in the fifth and sixth innings alone.
With Matt Shoemaker's return date hazy due to an oblique strain, the relief arms will now be asked to cobble together two starts through the rotation. The 'pen has been one of the Angels' biggest strengths this season, but on Tuesday, it let an early two-run lead turn into an 11-run blowout.
In their previous 78 appearances, the relievers had allowed 75 earned runs (2.39 ERA, second in the Majors across that span). On Tuesday, they allowed nearly one-fifth of that.
"These guys are good and they've been throwing the ball very well and they'll bounce back," Scioscia said. "[The Mariners] found holes, hit the ball hard and they beat us up pretty bad tonight."
In the first four innings, it was Angels starter Cory Rasmus doing the beating up. Rasmus, who was making his fourth career start, threw a career-high four innings, allowing just one hit.
Rasmus said he felt good after the fourth inning but an extended bottom half of the inning resulted in Scioscia yanking Rasmus after just 43 pitches. Scioscia said Rasmus' ceiling was about 50 pitches and that he was "pretty gassed" after the fourth.
"I told him 'I felt good, I'd like to go out there for another inning,'" Rasmus said. "At the end of the day, that's their call whatever they see. It's all about the team winning. Tonight, just happened that we lost."
Scioscia summoned Jason Grilli to replace Rasmus in the fifth. Grilli, who had a 2.35 ERA since being traded to the Angels, walked the leadoff man and then hit the next batter. Back-to-back doubles from Mike Zunino and Chris Taylor knocked Grilli out of the game with the Angels behind by one.
Mike Morin allowed an RBI double and escaped with the Angels trailing by just two. But Fernando Salas surrendered five runs on four hits, Joe Thatcher gave up another and Michael Roth allowed three more, with the game out of reach by the seventh inning when the Angels removed nearly every lineup regular.
"We had our bullpen lined up," Scioscia said. "We definitely felt good with getting our guys in and not having to stretch Cory. Unfortunately, it didn't work out."
With Shoemaker hurt, and inconsistency from C.J. Wilson and Hector Santiago, the Angels may need to stretch Rasmus in the last few weeks of the season to give the club another pitcher with length, and, possibly, a playoff starter.
Rasmus has never thrown more than 51 pitches and hadn't recorded 12 outs until Tuesday.
"He threw the ball as well as you could throw the ball, there's no doubt about it," Scioscia said. "There's an endpoint for him right now and he was there. … He did exactly what we wanted him to do, getting 12 outs and getting to a point in the game with the lead."
The 26-year-old right-hander has morphed from the bullpen's long-relief guy into a starter who said he'd like to go deeper into games.
"At the same time, I've only been starting, what now, four times?" Rasmus said. "So, you can't really get greedy with it, I guess. Got to make sure you work it outing by outing and build up."