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03/21/2013 9:48 PM ET

A's middle infield positions still up for grabs

GOODYEAR, Ariz. -- There are 11 days left until the Athletics open the 2013 season against the Mariners, but the team has yet to decide how the middle infield will be configured.

The second-base position has been up for grabs throughout Spring Training and manager Bob Melvin admits he is facing some difficult decisions.

"It could go down to the last three games against the Giants," Melvin said. "There's quite a pack in the infield at this point, and a lot of them are playing really well. We have to decide whether or not Spring Training means something for certain guys and not for others and what the best mix of guys to start with [is]."

Ultimately, Melvin will have to settle on a 25-player Opening Day roster as well as a nine-man lineup to face Seattle, but the manager was quick to point out that changes are a part of the game, and nothing is "etched in stone."

Fifty different players made at least one appearance for the Athletics a season ago, and Melvin expects the same sort of platooning to be used in 2013.

"With the personnel we have, mixing and matching [is what we expect to do]," Melvin said. "We've made no decisions on who is where and how much. A lot of guys are playing well, and it's making our decisions tougher. Having said that, it could be two guys that we lean on in the middle [infield], but I don't know that yet."

Among the plethora of players competing for spots in the Oakland infield are Jemile Weeks and Jed Lowrie, who started at second base and shortstop, respectively, on Thursday.

The competition for playing time is far from over, but both Weeks and Lowrie have been impressive this spring.

"Lowrie has been terrific," Melvin said. "Weeks got set back a little bit by his injury, so he doesn't have the amount of at-bats that other guys do, but he has swung the bat well."

Lowrie, who was acquired via a February trade with the Astros, was hitting .313 this spring, while Weeks entered Thursday's contest against the Reds with a .409 batting average.

Anderson will have different approach in final spring tilt

GOODYEAR, Ariz. -- Brett Anderson's stats may not have looked like those of an Opening Day starter, but he was able to take some positives from Thursday's start against the Cincinnati Reds.

"The results weren't awesome, but I take more positives than negatives from this outing," Anderson said. "[I] threw some good pitches, threw some not-so-good pitches [and] threw some pitches I wouldn't ordinarily throw in a regular season game."

Anderson threw 4 2/3 innings, allowing six runs on eight hits and striking out five. He now has a spring ERA of 9.45.

"He got his pitches in," manager Bob Melvin said. "He threw quite a few changeups to work on that, a couple of them got hit."

The left-hander began his outing sharply, striking out two and retiring the side in order in the first. However, that was the only inning in which Anderson faced the minimum number of batters.

In the second inning, Anderson allowed three extra-base hits and three earned runs.

"That was a really long top of the second there," Anderson said. "It took me a little while to get back into rhythm."

Anderson is expected to make one more Cactus League start prior to the Athletics season opener on April 1 and said he will approach that game more like a regular season tilt instead of working on certain pitches.

Melvin sees positives in Colon's uneven Minors start

GOODYEAR, Ariz. -- Oakland had a rare spring off-day Wednesday, but Bartolo Colon made an appearance with the Minor League team in order to keep his schedule intact.

Colon's final line -- 10 hits, two walks and five runs over five-plus innings -- is certainly nothing to drool over, but manager Bob Melvin was pleased with the report he received.

Melvin was not in attendance as Colon faced an Angels' Minor League team, but pitching coach Curt Young was on hand and reported back to the manager.

"There were a lot of balls on the ground, his velocity was good -- 90 to 93 -- maybe some poke hits, and [he] got a little tired at the end," Melvin said. "But [he] felt good, and with a guy like him, with his experience, [it's] more important [that he's healthy] and getting the pitches."

The Athletics were hoping to get around 80 pitches from Colon, who finished with 81. The right-hander has a 7.36 ERA in 11 innings pitched this spring, but Melvin is not concerned.

"The one thing about the few veterans we do have is they are serious about what they are doing out there," Melvin said. "He is working on some things. It's not like he's just throwing the ball up there. He's trying to get a good workout out of it and get something out of it."

Melvin said Colon, who threw 89 percent of his pitches for fastballs in 2012, has been working on his changeup and breaking balls.

Colon will miss the first five games of the regular season as he finishes up his suspension for violating Major League Baseball's drug policy. before he joins the team. However, Melvin remains undecided on when Colon will be worked into the rotation and make his debut.

Nakajima adjusting to Majors and new home

GOODYEAR, Ariz. -- Hiroyuki Nakajima's .176 Spring Training batting average is not where he or the Athletics organization would like it to be, but manager Bob Melvin is being patient.

Melvin is evaluating Nakajima differently than the rest of the players in camp because his situation is, well, different.

"It's easy to sit here and look at his performance … [but] he is having a lot of things he has to deal with that nobody else is," Melvin said. "He is going through a lot more."

The shortstop hit .311 in Japan last season, so the A's know he has talent and potential. However, Nakajima is adjusting to not only life in the Major Leagues, but to life in America as well.

"There's a learning curve for him right now, and everyone handles that differently," Melvin said. "It's difficult to come into this country and have to deal with the things he's had to deal with that aren't just on-field stuff."

While some of the off-the-field adjustments will come with time, the A's are trying to get the 30-year-old shortstop ready for the regular season as soon as possible.

Nakajima was not in Oakland's lineup Thursday, but he will get some at-bats with the Minor League team.

"[We are] trying to combat lack of experience here by getting him some more at-bats, but not overdo it to where we wear him out," Melvin said.

William Boor is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.