BOSTON (AP) -- The Boston Red Sox are confident that Mike Napoli can be their regular first baseman despite a hip condition that led to him signing a one-year contract instead of the original three-year agreement that had been reached.
"This has been caught very early," Red Sox general manager Ben Cherington said Tuesday. "There's, from all the information we have, a very good prognosis and no reason to think that Mike won't be a huge part of our 2013 team."
The contract Napoli signed on Tuesday is for $5 million with possible bonuses that could take its value to $13 million.
His condition is known as avascular necrosis, which can cause bone tissue to die because of poor bloody supply. His agent, Brian Grieper, said Napoli has it in both hips.
But Napoli, a catcher most of his career, said he's had no symptoms and didn't know he had the condition until it showed up during a physical required by the Red Sox after reaching the earlier $39 million deal.
"It was definitely a shock," Napoli, who is taking medication for the condition, said during a conference call.
"I never had trouble with it," he said. "I played with it last year. I feel fine. I'm doing everything in the gym right now."
Former baseball and NFL star Bo Jackson also had AVN, and his career was cut short, but Cherington said Napoli's case is "very different."
Napoli, 31, spent the past two seasons with the Texas Rangers after playing his first five for the Los Angeles Angels. He batted .227 last year with 24 homers and 56 RBIs and was chosen for his first All-Star game.
Other teams expressed interest in him after the hip problem surfaced, but the Red Sox were "the best fit for me," he said.
The Red Sox hope he can provide right-handed power in the middle of the lineup. In 19 games at Fenway Park, he hit .306 with seven homers and 17 RBIs.
Playing first base, where Boston has no returning veteran, will take less of a toll on his lower body, Cherington said.
"We know he can catch. He's done that a lot in the past," Cherington said, but "it makes sense in the short term to allow Mike to focus" on first base. "We have no reason to believe that he won't be ready on opening day."
Napoli has played 539 games as a catcher and 133 as a first baseman.
"I definitely feel comfortable" at first base, he said. "I feel like the more reps I get over there, the better I can be. It's definitely going to be a lot easier on my body. ... I'm confident I can stay healthy all year."
He played in 108 games last season but his production dropped sharply from 2011 when he posted career highs of a .320 batting average, 30 homers and 75 RBIs. For his seven seasons, he's hitting .259 with 146 homers and 380 RBIs.
The Red Sox made room for Napoli on their 40-man roster by designating right-hander Chris Carpenter for assignment. In his only season with Boston, Carpenter was 1-0 with a 9.00 ERA in eight relief appearances. He began the season on the disabled list following surgery on his right elbow in March.