KISSIMMEE, Fla. -- One of the most interesting position battles to watch this spring will be at third base, where Jimmy Paredes, Brett Wallace, Matt Downs and Chris Johnson are all battling for playing time. Johnson, the Opening Day starter at third last year, is trying to expand his resume by working out at first base this spring.

Johnson played first base in college and got reacquainted with the position while at Minute Maid Park this offseason, working out with Wallace and first base coach Bobby Meacham.

"It's going good," he said. "One of the things is just getting adjusted to the different sized glove, and you have a couple of things with pickoffs with the pitcher you have to work on. It's an easy adjustment."

Johnson lost his starting job last year to Paredes and was sent to the Minor Leagues in August, which is something he hasn't forgotten.

"I get jacked up thinking about it," he said. "Being in the big leagues is where you want to be and getting sent down is not really a good feeling. I'll just work that much harder not to let that happen again."

Astros' move to AL intriguing to Lee

KISSIMMEE, Fla. -- Carlos Lee reported Sunday to his sixth and perhaps final Spring Training camp as a member of the Astros, a team that has undergone a massive rebuilding phase since he signed his six-year, $100 million deal prior to the 2007 season.

Lee, who made the move to first base last season, still hasn't committed to playing beyond his current contract, but he was intrigued by the idea of perhaps returning to the Astros as a designated hitter when the team moves to the American League in 2013. He still hasn't ruled out retirement.

"It's going to depend a lot on my performance this year," he said. "If I feel that I can keep going and keep helping somebody to win, I'll keep going."

Lee, 35, batted .275 with 18 homers and 94 RBIs in 155 games last year, and he hasn't put up the same kind of numbers the last two seasons as he did during his first three years in Houston when he hit .306 and averaged 29 homers and 107 RBIs.

"Last year, I started really slow, but I kind of figured it out and worked hard on my hitting and had a great second half," he said. "I did what I'm capable of doing. Hopefully we take off in the same condition I was last year hitting the ball like I normally do."

Lee kept his baseball skills sharp in the offseason by working out with the Panamanian national team for four weeks.

Astros pitchers make good impression on manager

KISSIMMEE, Fla.-- After a week of throwing in the bullpen, Astros pitchers took the mounds of the back fields of Osceola County Stadium and faced off against the position players for the first time on Sunday. The players were instructed to track the pitches and didn't have to swing, though some did.

"We wanted the guys to take it easy," manager Brad Mills said.

Mills wasn't able to see all of the pitchers throw Sunday, but he was impressed with what he saw from Zach Duke, Juan Abreu and Henry Sosa, among others. Brett Myers, J.A. Happ, Jordan Lyles, Wesley Wright and Kyle Weiland were among those also on the mound Sunday.

Also making a good impression on Mills was veteran Brandon Lyon, who missed the final four months of last season following surgery to repair a detachment of his right biceps tendon and a tear of his labrum.

"I was pleasantly surprised with the way he threw and he said he felt good, which is even better," Mills said. "I thought he threw the ball pretty well."

Escalona, Paredes on the mend

KISSIMMEE, Fla. -- Left-handed reliever Sergio Escalona didn't throw to hitters Sunday and instead put in his work in the bullpen under the watchful eye of pitching coach Doug Brocail and head athletic trainer Nate Lucero. Escalona hurt his elbow last week swinging a bat and has been a few days behind schedule.

"It's getting better," he said. "When I was hitting I felt soreness and the next day when I was throwing I felt more pain. I threw light catch [Saturday] and threw the bullpen today and I feel great. It's getting better. I'm going to work on a couple of exercises to get my elbow stronger. It might be a little weak now. Maybe I didn't rest enough. I'll be ready for the season."

Escalona appeared in 49 games for the Astros last year, going 2-1 with a 2.93 ERA.

In other injury news, third baseman Jimmy Paredes didn't swing against live pitching because of inflammation in his left wrist, and infielder Angel Sanchez remains limited because of back problems, but his condition is improving.

"For the most part, we're healthy," manager Brad Mills said.

Top prospect Singleton in camp, ready to learn

KISSIMMEE, Fla.-- Jonathan Singleton, the club's top-rated prospect by MLB.com, reported to camp Sunday for the first time with the Astros. The first baseman was acquired by the Astros last summer from the Phillies as part of the trade that sent Hunter Pence to Philadelphia and is the gem of an ever-improving Minor League system.

"I'm looking forward to it," Singleton said. "It's definitely a new experience. My eyes are open."

Singleton, 20, is a non-roster invitee who's not going to make the big league team out of Spring Training. He said his top goal is to learn as much as he can from the staff and the few veteran players that are left on the club.

"It's a new opportunity to show another team what I have to offer, and I'm just going to play hard," he said.

The Phillies moved Singleton to left field to start 2011 in an effort to avoid the Ryan Howard roadblock, but after a couple of months, they moved Singleton back to first, where he is much better defensively. He's expected to begin 2012 at Double-A after hitting a combined .298 with 13 homers and 63 RBIs last year between Class A Clearwater (Phillies) and Lancaster (Astros).