That bullpen depth had reached its end, however. Jim Johnson, the closer when the season started, was the last man standing. He had to get the last six outs, and he did, as the A's defeated the Angels, 10-9, in 11 inning for their fourth victory in a row.
"Jim Johnson was terrific," manager Bob Melvin said. "That was huge. I didn't have [Luke] Gregerson or [Fernando] Abad tonight, so it was his game. He knew it, and that was impressive."
Johnson (2-2) lost his closer's job April 9, but has made three scoreless appearances covering five innings since, including Tuesday's two-inning stint.
"It's so early," Donaldson said, "so quick to jump to any conclusions about a guy. He didn't save 100 games the past two years for no reason. The guy's good."
The Angels' Mike Trout hit a two-run homer off left-hander Sean Doolittle in the bottom of the ninth to tie it at 9.
"I threw a thigh-high fastball in the middle -- that's never good," said Doolittle, closing because Gregerson, who closed the two of the past three A's victories, wasn't available after pitching three days in a row. "You let the leadoff guy on [Kole Calhoun doubled], that's opening Pandora's Box anyway.
"There's nothing to say. I messed that up."
The A's had rallied late for the second night in a row, this time for four runs in the eighth inning against Angels reliever Joe Smith, to take a 9-6 lead on Jackie Robinson Day.
A's starter Dan Straily couldn't get out of a four-run Angels fourth inning punctuated by Calhoun's two-run home run, which gave the Angels a 6-3 lead. A's starters had allowed three earned runs or fewer in each of the season's first 13 games before Straily allowed six in 3 2/3 innings.
But Smith, who hadn't allowed a run in six previous outings, didn't retire any of the five A's he faced in the eighth, walking three and giving up RBI singles to Brandon Moss and Alberto Callaspo.
"I was absolutely terrible tonight," Smith said. "There's no other way to say it. That's as bad as I've ever performed."
His relief, Jose Alvarez, was greeted by pinch-hitter Derek Norris' two-run single for a 9-6 A's lead.
"It was like three different games," Melvin said. "We got behind early and came roaring back again. Give credit to them -- Sean Doolittle's not an easy guy to score two runs off of. Doolittle very rarely does that."
The A's have this catcher-in-a-pinch thing down. On Monday night, John Jaso hit a pinch-hit, two-run homer in the ninth off Ernesto Frieri for a 3-2 Oakland win. This time, it was Norris' turn to deliver the hit that would've been the difference had Doolittle been able to hang on.
"They never say die," Melvin said of his team, adding "whatever happens, it doesn't bother them. They come back in the next inning fighting."
David Freese singled in an Angels run in the bottom of the eighth.
Angels starter Garrett Richards allowed five earned runs on eight hits in seven innings. He struck out five, but walked Josh Reddick twice, and the .098 hitter scored both times.
The A's cut their deficit to one run by scoring twice in the seventh on the second RBI single of the night by Eric Sogard, plus a wild pitch.
Sogard was just 2-for-17 on the road trip before his first RBI single got the A's rolling in a three-run third inning. That hit snapped an 0-for-23 streak by the A's with runners in scoring position. It was also Sogard's first RBI this season.
Jaso followed Sogard with an RBI grounder, then Lowrie -- who had three hits, plus a key walk in the eighth -- doubled home Sogard to put Oakland up, 3-2.
But Straily couldn't hold it. Drew Pomeranz, the first of five A's relievers, pitched 2 2/3 scoreless innings to set up the first rally.
"Pomeranz came in and gave us a chance to come back," Donaldson said. "It's one of the few times all year one of our starters struggled a little bit."