Joe Mauer has spent too much of his career with doctors.

"I now know why they call it practicing medicine," Mauer said, "because there are so many different opinions out there as to what to do and what not to do. But it's your body and you are the only one who knows how you feel and you gotta try to go out there and do the best you can."

Instead of discussions about his three batting titles or 2009 MVP Award, Mauer has been a lightning rod for debate about how often he's been out of the lineup over the years because he was too banged up to play — or was flat out injured. Since his debut in 2004, Mauer, 30, has started only 885 of 1,622 regular-season games behind the plate (54.6 percent). The local sports lexicon includes such phrases as stress reaction, sacroiliac joint and bilateral leg weakness just from tracking Mauer's career.

Now forced from behind the plate following a concussion last season, Mauer hopes the combination of years of tweaking his workout plans and moving to first base will keep him on the field the entire season — and discussions will center about how durable he's become.

Just being on the field more, Mauer notes, should lead to better numbers. For instance, he hit 11 home runs and drove in 47 runs in 113 games last year. Projected over 162 games, that's 15 homers and 67 RBI. Instead of hitting 28 homers with 96 RBI in 138 games in 2009, he would have had 32 homers and 112 RBI over 162 games. Sure, who plays 162 games anymore? But the important thing is having one of the best hitters in the game in the lineup as much as possible.

Mauer spent spring training enjoying life as a first baseman. He usually reports to camp weighing around 235 pounds, then loses 7 to 8 pounds before Opening Day. He has fought through the years to keep his playing weight around 227. He reported this year at 228, no longer needing to build up a base weight that's usually knocked down by catching in camp.

Now he is liberated from catching drills. Just working on blocking balls in the dirt can make legs feel like they are on fire.

"My knees feel pretty good," Mauer said. "That's the thing I'm trying to figure out more than other things, how to maintain that strength. My leg workouts in the past have been through bullpens and catching the game. Make sure you stay loose — that was probably good enough. But first base, you are not up and down a lot.

"So I found I have to do a little bit extra in the weight room and the training room to stay strong. That's going to be something that I will continue to learn as we go. But it definitely feels different physically than in the past."

Catchers across the league worry about keeping their legs strong, and Mauer's challenge has been greater because he's 6-foot-5. There's no squatting at first base — and he doesn't have to worry about foul tips clobbering him.

"I think the volume of activity that he saw as a catcher was exponentially more than the volume of activity he's going to see at first base, in the aspect of the stressful amount of work he will see," said Perry Castellano, Twins strength and conditioning coordinator. "The adjustments will allow him to keep himself looser and hopefully work on his longevity."

Mauer's midcareer migration to first base is an opportunity for him to put his disabled list stints in the past. Castellano will help design an offseason conditioning program fit for a first baseman. Mauer can spend more time with Twins doctors on the golf course than in the training room. His fresh hands and fresher legs could keep him in the lineup more, where the Twins hope he will do more damage with his bat.

"He hates being hurt, no doubt about that," said Jake Mauer, Joe's brother and manager at Class A Cedar Rapids. "That's probably the worst for him, going through the rehab and all that garbage. It's not fun watching teammates play and you can't. And I know he was pretty miserable the last two years.

"If he stays healthy, he's going to hit around .320, .330 and is going to produce more runs, and he will be fresher longer and feel better for longer periods of time.''