Notes: Josh Hamilton lighter, quicker?

SURPRISE, Ariz. -- Josh Hamilton was out on the back fields early Saturday, practicing charging balls with some of the other outfielders in camp.

But it's lighter Hamilton this spring, by about 15 pounds he figures. Hamilton said he's arrived in Surprise at 225 pounds, down from the usual 240.

"I feel like it's better for my joints and quickness," Hamilton said.

Hamilton also altered his offseason mentality a bit. He decided to prepare as if he's going to be playing center field every day. The Rangers, of course, would not prefer that. They'd like Craig Gentry, Julio Borbon, Leonys Martin or someone else to seize that spot so that Hamilton could stay in left as often as possible.

That's why Hamilton felt coming in lighter was the smarter move. He wants to make sure he can cover as much ground as possible and that losing the weight will help.

Hamilton reiterated that he doesn't care where he plays in the outfield. But he wants to be prepared for wherever he needs to play. He did admit center field is his natural position.

"I've played it more in my life than anywhere else, so it's natural," Hamilton said. "But I've played the other positions too."

Hamilton put a Pilates routine back into his offseason regimen, something he said he did prior to the 2008 and 2010 seasons. He just felt like doing it again to see if it would help his overall balance and strength. All of it is with the intention to try to do what he can to stay healthy. He's played a full season just once in his career, in 2008 (156 games).

Other notes:

* Manager Ron Washington made it clear Saturday that center field is open this spring. And the contenders are here in camp already with the first full workout slated for Sunday.

* Julio Borbon believes a full season of winter ball has helped him improve. His ankle feels good and he certainly looked more self-assured and confident to me in the clubhouse Saturday morning. Maybe having to fight for the center field job will help him.

* Craig Gentry has the benefit of getting quality time in the big leagues last year and playing time in the postseason. His confidence is high, too, and he knows he has a great opportunity to win the job.

* We'll see if Leonys Martin can push his way forward as well. The club is high on him, but he's still got just a few months of minor-league action under his belt.

* Washington said he'd prefer to split left-handed pitchers Derek Holland and Matt Harrison in the rotation but wouldn't say how that would line up. They'll make those decisions later this spring.

* Yu Darvish will throw a five-minute bullpen session and five minutes to hitters this morning as well.

* All position players are accounted for and ready for Sunday's first full squad workout.