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8/29/2013 2:16 P.M. ET

Lasik surgery puts Smith on 'even playing field'

DETROIT -- For Seth Smith, the process of fixing his hitting woes started with fixing his vision, or at least improving it.

The A's outfielder and designated hitter underwent Lasik surgery for the second time in seven years last week to correct the astigmatism in his left eye, and on Tuesday, he hit his first home run in 39 games.

Coincidence? Not likely.

"Everything is more defined, so I don't know if I'm picking up spin more, but just the whole picture is clearer, as opposed to it being a little bit off," Smith said Thursday morning. "When you get that out of your head, it allows you to focus on the task at hand, rather than any deficiencies you might have."

Smith by no means expected "some miracle that would make me better than I was," but the procedure has given him back the confidence that's been lacking for a while. Smith hit .267 before the All-Star break, but is batting just .115 since.

"That's the main thing it's done," he said. "I feel like I'm on an even playing field."

"I know he's been struggling here lately and looking for some comfort at the plate, and we've seen really good signs," said teammate Brandon Moss. "Obviously, he's a big bat in our lineup, and we definitely need him. His at-bats lately have been really good. Really good."

Smith began noticing a slight difference in his vision not too long ago, mostly on the field. But then there were times, even off the field, where he noticed he could see much better out of his right eye than his left.

Smith had Lasik surgery on both eyes back in 2006, so he wasn't afraid to undergo the speedy operation again -- this time, it took a total of four seconds, he said -- when realizing the astigmatism had partially returned. He went in during lunch hour on a Tuesday and was driving himself to a checkup appointment the next morning. Two days later, he was back in the A's starting lineup.

"I just knew it was affecting me a little bit, and this game is so hard as it is, that you want to give yourself every advantage that you can," he said. "So it was something where it was worth missing two days to feel like you're going to be better for the long haul."

With DL returns, callups, A's roster could be packed

DETROIT -- The A's typically keep their September roster additions to a minimum, but that likely won't preclude them from boasting a packed house down the final stretch this year.

Aside from the predictable bullpen help expected to arrive -- Tommy Milone, Evan Scribner and Pat Neshek lead the list -- and perhaps some extra speed -- think Jemile Weeks -- the A's roster will be longer than normal, with the potential return of injured players Josh Reddick, Derek Norris and John Jaso.

There are also the players who warrant a callup based on their work in the Minors, notably outfielder Michael Choice, who is batting .300 with 14 home runs and 89 RBIs in his first full season with Triple-A Sacramento.

"With the guys that we have on the DL alone, and guys like Milone and Neshek, and then add some people that probably deserve to be there, you could see a few more this year," said manager Bob Melvin.

That doesn't mean Melvin is a big fan of Septembers.

"I don't like all the callup stuff. I really don't," he said from Comerica Park on Thursday. "It's much more difficult to prepare for teams. You don't know how they're going to use their bench. To me, it's a bit of a distraction that I'm just not a huge fan of. ...

"I could see calling up as many guys as you want, but maybe designate 27 guys a game, maybe 28. But when you have seven, eight, nine more guys over there, it's more confusing."

Catchers Norris, Jaso making strides in rehab

DETROIT -- The A's could soon have four healthy catchers on their roster, should Derek Norris and John Jaso continue making strides in their respective rehabs.

Norris, who broke his big left toe just last week, is progressing so well that he could play in a rehab game as soon as Saturday, according to manager Bob Melvin. His fracture has not completely healed, but "enough to where he's running around and feeling fine on it," Melvin noted.

And Jaso, who for more than a month wasn't able to participate in any baseball activities because of ongoing concussion symptoms, played catch for the first time on Wednesday and could take batting practice at some point on the club's 10-game homestand that begins Friday.

"He felt pretty good," Melvin said. "When we get home, he might take batting practice with us, so we're starting to get more encouraging signs from him."

Norris is eligible to be reinstated from the disabled list on Sept. 5. Rosters will have expanded by then, allowing the A's to keep all of their catchers, including current platoon mates Kurt Suzuki and Stephen Vogt, in tow.

With little fanfare, Callaspo producing for A's

DETROIT -- The A's reeled in Alberto Callaspo in a trade with the Angels before July's non-waiver Trade Deadline without much fanfare, and the veteran infielder has since provided consistent production in much the same fashion.

Callaspo, swapped for infield prospect Grant Green, has quietly hit .309 with a .400 on-base percentage and nine RBIs in 24 games since joining Oakland, including .368 with a .456 on-base clip in the last 19 games.

His ability to put the ball in play is perhaps no more evident than by looking at how many times he's missed it. Callaspo has struck out just 32 times on the season, and his average of one strikeout per 13 plate appearances is the best mark in the American League.

"Whether it's right- or left-handed, he seems to be getting the barrel on it," said manager Bob Melvin. "It's not a guy you expect to hit a bunch of home runs for you, but you expect him to put the ball in play, hit line drives. He's been knocking in runs. He's been extending rallies. Also another guy who's been very versatile where you can hit him in the lineup."

The switch-hitting Callaspo was one of eight lefties the A's threw at Tigers starter Max Scherzer on Thursday. It marked his 12th start with the A's at second base, but he's also appeared in the designated hitter slot five times. That's five more times than manager Bob Melvin probably ever envisioned using him there.

"Using him in the DH spot," Melvin said, "I wasn't sure if that was going to be part of the dynamic, but he's certainly earned it."

Worth noting

• The morning after lefty Brett Anderson threw 56 pitches in a three-inning relief appearance in Detroit, there was still no clarity on his role moving forward. Much of it will depend on how Bartolo Colon, activated from the disabled list Thursday to start against the Tigers, fares in the coming week.

"He just is where he is right now," Melvin said of Anderson. "We'll see how Bart does. He gives you some things in the bullpen that some guys can't. Whether we look to him to give us an inning against a couple of lefties. ... It kind of depends on how everyone's performing around him. He's added depth in the bullpen at this point, a guy that gives you versatility."

• To make room on the roster for Colon on Thursday, the A's optioned Scribner to Triple-A Sacramento. Scribner, expected back in September, was recalled Monday for his fourth stint with Oakland, but he did not appear in a game.

• In partnership with Chevron, the A's on Saturday will host the Chevron STEM Zone, an exhibit that explores scientific concepts behind the game of baseball. Admission to the STEM Zone, located behind Section 217, is free to fans with a ticket to that night's game against the Rays.

Jane Lee is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.