Guerrero, who turned 35 earlier this month, said he lost some weight in the offseason and worked on strengthening his knees. He had surgery on both knees before the 2009 season.
"I feel good," said Guerrero, following the Rangers' first full-squad workout Wednesday. "I was sharing some time with my teammates. I know some of them, but it's time to get acquainted."
It wasn't difficult to find Guerrero on Wednesday. A throng of fans, not to mention a handful of media, followed Guerrero from field to field. And many watched as he launched a few balls during batting practice and caught fly balls in right field.
Guerrero said he's prepared to be the designated hitter and play in the outfield.
"I came here to play," Guerrero said. "It's up to them if they want to use me as a DH or play the outfield. I have to work and prepare to play both places."
Manager Ron Washington said that he will get Guerrero some games in right field. But his primary concern is keeping his cleanup hitter healthy. He wants him to play 150 games.
Guerrero hasn't played that many since 2007. He played in just 100 games last season. He missed 35 games early in the season with a torn chest muscle and then returned to the disabled list in July, missing 21 games with a strained left calf and strained left hamstring. When he did play, Guerrero hit .295 with 15 homers and 50 RBIs.
Guerrero said it was a three- or four-hour conversation with Washington at Guerrero's California home that sold him on Texas.
"The way he treated me convinced me right away to sign with the Rangers," Guerrero said.
Washington isn't concerned about Guerrero's penchant for not taking many pitches. He averaged 3.2 pitches per plate appearance, last in the American League among hitters with at least 375 at-bats.
"He can do more damage than most," Washington said. "We just want him to be Vlad. He'll make an impact."
Infielder Michael Young joked that Guerrero probably knows him as "a guy with horrible Spanish." But Young is clearly excited about having Guerrero around the clubhouse and in the lineup.
"I can't wait to get started with the guy," Young said. "I've had a chance to really play with some great hitters here in Texas. The list is long. This is another Hall of Fame guy I get to play with."
Young disputes the notion that Guerrero simply swings at everything he sees.
"Obviously, he's ultra-aggressive," Young said. "But I've seen him get in an 0-2 count and our pitcher would throw three of his best pitches out of the zone and he wouldn't budge. Now, all of a sudden, he's sitting back in a full count and can get a good pitch to hit. He doesn't [get] enough credit for being disciplined at times. He does have a good idea of what he's doing up there. He's not just a guy going up there taking his licks. He has a plan and knows what he wants to do and he executes it as well as anybody in the game."
Young has watched Guerrero pound the Rangers during his career, especially in the last six seasons with the Angels. Guerrero has a .396 batting average with 24 homers and 66 RBIs in 102 games against Texas. Guerrero's favorite road park was Rangers Ballpark in Arlington. He hit .394 there in his career, the top average among any park with at least 100 at-bats. Guerrero has 14 homers, 33 RBIs and a .705 slugging percentage at the ballpark. The Rangers plan on him building upon those numbers in 2010.
Guerrero's presence in the lineup at the No. 4 spot should also give Josh Hamilton greater protection and more fastballs to hit.
"But it's up to me to lay off the balls and be a more disciplined hitter so that having him hit behind me really helps me," Hamilton said. "He's a dangerous hitter and we're glad we have him."