FORT MYERS, Fla. -- Left-hander Jose Mijares made quite an impression during his call up to the Twins last September.

But with Mijares having been promoted straight from Double-A New Britain, Minnesota officials repeatedly said this winter that he'd have to earn his spot on the roster this spring.

And if he's going to be with the club to start the 2009 season, Mijares will need to make a few adjustments.

Mijares had another so-so outing for the Twins on Saturday. He pitched one inning, allowing one run on two hits. He tweaked his ankle slightly in the outing, but manager Ron Gardenhire seemed more concerned about Mijares' pitching performance.

"He's still trying to work through his mechanics," Gardenhire said. "He's overthrowing the ball. And he's got a few things we're trying to take care of. Hopefully we get him straightened out and see where he goes from there. We said all along that he's not a lock."

There have been a few areas of concern early this spring with Mijares.

In four innings of work this spring, Mijares has issued five walks. That's after he did not issue a single walk in 10 1/3 innings with Minnesota last fall.

Another worry of the Twins has been Mijares' physical conditioning. One of the last things Gardenhire told Mijares at the end of last season was to arrive at camp in shape. But Mijares, 24, arrived in Fort Myers looking to have put on a few pounds rather than having lost them.

"He came back in a shape," said Gardenhire, after mentioning earlier that Mijares looked out of breath in his one inning Saturday.

The Twins' hope is to get Mijares back on track with his workout and diet plan, in addition to getting his mechanics back in order.

The expectation heading into the spring was that Craig Breslow and Mijares would fill the roles as the left-handers in the Twins bullpen. But while the Twins would like to have two lefties in the 'pen, it's not necessarily a given, according to Gardenhire.

"You would like if [Mijares] could come and do what he did last year, he could really help you out in the seventh and eighth inning," Gardenhire said. "He got some big lefties out and some big righties out. We'll see. I don't want to put too much pressure and say that's his job. It's not his job. He can go out there and earn that job. But that's what he has to do. He's in a battle with a lot of guys here in camp."