"Yeah, Cookie had his ground ball going," said Red Sox manager Bobby Valentine. "He had one fly ball until the last one. We were hoping for one more there. Instead, it turned into a two-run homer. He had about, I don't know, counting the outs, the hits, probably 20 ground balls. He had his sinker going. It just wasn't placed well early in the game, and the two-run homer kind of did him in."
The loss came at the start of a seven-game homestand and the day after a change was made at pitching coach, with Randy Niemann replacing Bob McClure.
With 39 games left in the season, the Red Sox fell to 59-64 -- the first time they've been five games under .500 since May 12.
What is the team's mindset as they play the final quarter of what has been a thoroughly frustrating season to date?
"Play better collectively as a group," said outfielder Cody Ross. "It's not playing together. It seems like we get chances, opportunities and we have the pitcher on the ropes, and then we let him off the hook. I don't know if we try to do too much or what."
Cook went five innings, giving up 11 hits and five runs, four earned. He walked one and struck out four.
Daisuke Matsuzaka turned in a dazzling rehab start for Triple-A Pawtucket on Tuesday, so there's a chance Cook's spot in the rotation could be in jeopardy. The righty is 3-7 with a 4.79 ERA.
Is the rotation uncertainty weighing on Cook?
"Nope. Not one bit," Cook said. "It's not my decision. I'm just going to take the ball and throw when they tell me. Whatever happens, happens."
The Red Sox are 13 games back in the American League East and trail by eight games in the Wild Card standings.
David Ortiz remains out with a right Achilles injury, and Boston is without Will Middlebrooks and Carl Crawford for the rest of the season.
That makes life even tougher when they fall behind early.
"You're talking about [three] huge parts of this team, but at the same time, you can't make excuses," Ross said. "Every team has superstars that get hurt throughout the year, and we have to pick those guys up, and we're not doing that right now."
The Angels jumped out first, as Mike Trout started a third-inning rally with a one-out single up the middle. Cook's throwing error on a pickoff attempt allowed Trout to go to second, and Albert Pujols made it a 1-0 game with a two-out RBI single up the middle.
It was the second straight start Cook has cost himself with a throwing error.
"It bugs me a lot," Cook said. "Unfortunately right there, I had him picked off if I make a good throw."
Cook didn't settle down. Instead, the Angels continued to chip away. They got three straight one-out singles in the fourth -- the final one an RBI single by Erick Aybar. Chris Iannetta smoked one off the glove of shortstop Mike Aviles for another RBI single, pinning the Red Sox in a 3-0 hole.
In the fifth, it got worse. Trumbo smashed a prodigious two-run blast that soared over everything in left. It was No. 30 on the season for the 26-year-old.
"That ball was absolutely killed," said Angels manager Mike Scioscia.
Stifled by Ervin Santana over the first five innings, the Red Sox finally got a big hit in the sixth, a two-run shot by Jarrod Saltalamacchia that made it a three-run game.
Scott Podsednik tried to keep the pressure on the Angels with a one-out double in the seventh. He moved to third on a groundout and scored on a wild pitch, pulling the Red Sox within two.
In the eighth, Boston had runners at first and second with two outs, but Aviles hit a hard groundout to second to end that threat.
The Red Sox went down 1-2-3 in the ninth, falling to 29-35 at Fenway Park.