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10/4/2013 8:58 P.M. ET

Otero figures to play key role in ALDS

OAKLAND -- While much of the focus on the A's American League Division Series with the Tigers remains on the teams' stacked starting staffs, these games are surely about to magnify the importance of the bullpens, too.

Advantage: Oakland.

That's not just because one of the league's best closers in Grant Balfour is joined by two of the league's best setup men in southpaw Sean Doolittle and righty Ryan Cook. Right-handed rookie Dan Otero is another big weapon and figures to be a significant piece in his first postseason.

In fact, manager Bob Melvin has no problem including Otero, a quiet waiver claim in March, in any conversation about his setup men. And given his recent numbers -- he didn't allow a run over his final seven regular-season appearances -- Melvin might be more inclined in a big, late-inning situation to go with Otero over Cook.

Cook was 2-2 with four blown saves and a 4.11 ERA over his final 21 regular-season appearances, though it's worth noting he's never allowed a run to the Tigers in 5 1/3 career innings.

"He's gotten lefties out; he's gotten righties out," Melvin said of Otero on Friday afternoon before Game 1. "You look at his numbers, his ERA, and everything, he's put himself in this position to be a guy that we rely on, whether it's one-plus inning in an even game, whether somebody has a day off and he pitches the seventh, bring him in with guys on base with the sinker. He's pitched himself into this role, and I do consider him one of those guys, as far as setup goes."

Otero appeared in 33 games for the A's after being promoted from Triple-A Sacramento on June 14. In that time, the righty gathered a 1.38 ERA, not once allowing a home run in 39 innings. He struck out 27 and walked just six.

In comparison, the Tigers have Al Alburquerque and Drew Smyly bridging the gap to closer Joaquin Benoit. Past that, they're rather thin, and the bullpen compiled a 4.01 ERA, which ranked fourth from the bottom in the AL. Oakland's relievers, meanwhile, posted a 3.22 ERA, good for third-best in the league.

Griffin could begin throwing Saturday

OAKLAND -- Rehabbing hurler A.J. Griffin, who still hopes to factor in the A's postseason plans once healthy, has yet to begin throwing, though he could as soon as Saturday.

"I think we're going to make sure that he doesn't feel anything in his treatment and so forth, and when he gets past that, he'll start playing catch," manager Bob Melvin said on Friday. "That could be tomorrow."

Griffin, sidelined by tendinitis in his right elbow, was expected to start a potential Game 4 of the American League Division Series against the Tigers, as he did last year. But that nod went to Dan Straily when the A's decided they needed to rest Griffin.

Griffin said this week he hopes to be ready to pitch in the AL Championship Series, should Oakland advance.

Worth noting

• The A's have seven players appearing on their first postseason roster: infielders Daric Barton and Eric Sogard ; catcher Stephen Vogt ; and pitchers Sonny Gray, Jesse Chavez, Dan Otero and Dan Straily.

Of the 25 players on the A's American League Division Series roster, 13 were on the A's ALDS roster last year. An additional five players (Alberto Callaspo, Bartolo Colon, Jed Lowrie, Kurt Suzuki, Chris Young ) have postseason experience with other teams.

• Bob Welch, who won a World Series championship with the A's in 1989, is slated to throw out the ceremonial first pitch before Game 2 on Saturday, airing at 6 p.m. PT on TBS.

Welch was 17-8 with a 3.00 ERA in 33 starts with the A's during their 1989 championship season and two years later was named the AL Cy Young Award winner after posting 27 wins and a 2.95 ERA.

Dave Henderson, who was also on that '89 team, threw out the first pitch at the Coliseum on Friday.

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.