Lee said Monday that he's "perfectly fine" and the strain under his left armpit is "not really a major issue." He completed his next two pitching sessions last week, and took part in fielding practice during the first week of spring training.
Lee signed a five-year, $120 million contract with the Phillies as a free agent in December. He said he felt discomfort while playing catch last month in Arkansas.
"I had a little minor ... something going on in my armpit," Lee said at Phillies camp Monday. "I called the trainers, went to Philadelphia, and they diagnosed it. I didn't throw for a few days, built back up and here I am. I'm perfectly fine and right with everyone else. It's not really a major issue."
"He's 100 percent," Phillies general manager Ruben Amaro Jr. said.
After Lee's abbreviated session last Tuesday, pitching coach Rich Dubee brushed aside questions about the ace pitcher's health.
"It's kind of where he's at," Dubee said, explaining that pitchers come to camp at different stages of their throwing program.
Lee, 32, is no stranger to spring training setbacks. He pitched in two games a year ago while with the Mariners in Cactus League play after suffering an abdominal strain. He was activated from the disabled list April 30.
Lee continued on with the 2010 season injury-free, pitching 212 1/3 innings in 28 games with the Mariners and Texas Rangers in 2010.