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8/19/2013 9:35 P.M. ET

A's sticking with platoon at catcher

OAKLAND -- The A's have been consistent with their platoons this year, only straying from the formula when absolutely necessary because of an injury or other unforeseen scenario.

Expect it to stay that way -- even at catcher, despite Derek Norris' ongoing hot streak at the plate, partly because of some lingering back issues he first experienced in Toronto on Aug. 10.

Norris, batting .400 over his last 12 games, sat on the bench Monday with right-hander Aaron Harang pitching for Seattle, allowing left-handed-hitting backstop Stephen Vogt to make his 16th start since being recalled July 25.

"We're pretty strict with it right now, but I think more than anything it's about the back issues he's been having," said manager Bob Melvin. "It started to bother him at the end of the game yesterday again, and with a left-hander going tomorrow [Joe Saunders ], it definitely makes sense to give him a day off today.

"Until we get him back and healthy, we'll try to limit him to left-handers."

Norris has 12 hits in his last 30 at-bats, just as many as he totaled in his previous 52 at-bats. Since July 1, he's hitting .346 with a .443 on-base percentage, after compiling a dismal .162 clip in the two months prior.

But so long as a firm platoon remains in place, Norris will likely only garner one start over the A's next two series against Seattle and Baltimore, with the Orioles expected to pitch three right-handers.

Crisp's return gives A's back their 'motor'

OAKLAND -- The A's are far better with Coco Crisp in their starting lineup, even when he's not swinging the bat well.

Just consider the 55-37 record they've compiled on such days.

"He's our motor. He's our guy that gets us going," said manager Bob Melvin. "The running game suffers when he's not in there. We feel a little bit better about running behind him when he's running. When he's playing well, we're usually playing well. There are certain guys that have a little more impact to your team than others, and he is definitely one of those guys for us."

The A's were obviously thrilled, then, to get Crisp back on Monday for the opener of a three-game set against the Mariners, marking the first time their regular leadoff hitter had appeared in the starting lineup since Aug. 11.

Blame it on a sore left wrist, which has bothered Crisp off and on this season, perhaps explaining the veteran outfielder's ongoing struggles at the plate. He's batting just .191 over his last 46 games after hitting .301 over his first 50 contests.

In this ugly stretch, Crisp has also watched his on-base percentage slide from .386 to .329. As a result, his stolen-base attempts have dwindled, and he only has three successful ones in that span. On the year, he has 16 stolen bases, putting him on pace for 21.

His 162-game average in 11 previous seasons? 35.

"He just hasn't been on base as much," Melvin said. "The wrist thing, he's had it a couple of times this year. One time he played through it and, the last time obviously, we had to get him a [cortisone] shot and sit him down. So whether or not that's contributing to some numbers, more of a question for him. But he is a tough guy that wants to play through injuries when he can."

The switch-hitting Crisp has more issues with his wrist when batting right-handed, so Melvin said he's likely to rest him again on Tuesday with lefty Joe Saunders going for the Mariners. Then he could start Wednesday and again rest Thursday, thanks to a team off-day.

From there?

"We'll just see how it goes," Melvin said.

"With something like that," explained, "I don't know that even when you rest a guy, he's still taking swings in the cage, trying to prepare and get ready."

Otero earning trusted role in A's bullpen

OAKLAND -- Relief pitcher Dan Otero's struggles following his callup to Oakland in the middle of June suggested that perhaps the move was slightly premature.

Then he proved otherwise.

After allowing three runs in his first four games with the A's, the right-handed Otero has not yielded a run in 13 of his past 14 appearances, recording a miniscule 0.42 ERA over 21 2/3 innings.

Gradually, his role in the bullpen has shifted as a result -- in a good way. Otero, who pitched in 12 games for the Giants in his first taste of the big leagues last year, is no longer simply being used to eat up innings with the A's trailing, rather he's been trusted to hang onto leads.

Take Sunday, for example, when he replaced starter Tommy Milone with two outs and a runner on second base in the fifth inning, his team clinging to a 5-3 lead against the Indians. He needed just three pitches to force an inning-ending groundout from Ryan Raburn, before compiling four more outs while allowing just one hit.

"Otero's been a real unsung hero for us recently," said manager Bob Melvin. "To give us an inning and two-thirds when he's finishing out the fifth, pitching the sixth and one batter in the seventh, that's a pretty good outing for us.

"You look at his numbers right now and they're really indicative of the way he's pitched. Bridging that gap to 7-8-9, that's huge for us."

Said Otero: "This is the type of pitcher I feel like I am, just throwing strikes and getting ahead of hitters and then trying to put them away as quickly as possible. I'm just pitching my strengths."

Worth noting

• The location of lefty Brett Anderson's second rehab start has been decided. He will pitch in Stockton for the Class A Ports on Thursday, rather than go with the Triple-A River Cats to Colorado Springs.

Not only did travel factor into the decision, but, "I don't know that Colorado Springs is the greatest environment to pitch in, either," manager Bob Melvin said.

Anderson is expected to throw close to 70 pitches, after throwing 49 and allowing two runs on three hits and three walks with two strikeouts in 2 1/3 innings in Sacramento on Sunday.

Josh Donaldson entered Monday having compiled multiple hits in each of his previous two games. He has 42 multihit games on the season, which are the most by an A's player since Adam Kennedy had 45 in 2009.

Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.