Jason Giambi expects to make a full recovery from health problems that have slowed him this summer and is confident he will return to the New York Yankees' lineup before the end of the season.

The four-time all-star declined to discuss details of his condition or the benign tumor found in an undisclosed spot in his body last month, but did say it was not related to an intestinal parasite the Yankees diagnosed earlier in the year.

"It's been a pretty traumatic experience," Giambi said during a news conference on Wednesday at Legends Field, the club's spring training home.

"The biggest thing is I'm going to recover 100 percent. . . . I don't want to get into the specifics. That's something I'm going to deal with my family. I'm excited to get down here, get back playing again, getting a chance to start over. It's been a tough two months."

Giambi was cleared medically to resume baseball activities on Monday, when he arrived in Tampa to begin working himself back into playing shape. The slugger spent about 90 minutes in the weight room before meeting with reporters, and he plans to begin swinging a bat early next week.

The first baseman, who has felt weak for most of the season, has not played since July 23. The Yankees at first diagnosed him with the intestinal parasite, then said on July 30 that he had a benign tumor, without disclosing where it was located.

Giambi has been working out and throwing occasionally for about two weeks. Now that he's in Tampa, he's on a daily schedule designed to build the strength and endurance necessary to be a productive everyday player.

There's no definitive timetable for his return.

"My goal is to be back on the field before the end of the year. There's no doubt about that. It's going to be how quick my body bounces back," Giambi said.

"I also want to be the player I can be. I don't want to just be a body like I was before out there. It was nice to see your name in the lineup. But when you're a player that people are expecting big things from -- and I expect them from myself also -- that's what I need to be."

Giambi conceded it was scary not knowing what was ailing him. Still, he continued to play.

"I felt like a lab rat during those times. . . . The not knowing, that was the worst part of it. You start to go, 'Why am I not getting better?' " he said.

"It eventually came to a point where I just wasn't helping the team. I wasn't being the Jason Giambi I can be. That's what the New York Yankees signed me to be. I want to be that guy."

Giambi had difficulty keeping food down for much of June and July. Before he was put on the disabled list, he was hitless in 21 consecutive at-bats, dropping his average to .221. He has 11 homers and 36 RBI after batting .250 with 41 homers and 107 RBI last season.

"I wasn't being the Jason Giambi I can be. . . . I want to be that guy," says Yanks' 1st baseman, out since July 23.