Prior to the Red Sox officially signing Napoli during the offseason, a serious hip condition called avascular necrosis was discovered during a physical.
He arrived at camp earlier this week and had another MRI taken Thursday to make sure his hip had not gotten worse.
"Nothing got worse, it stayed the same. It's what we wanted," Napoli said Saturday morning.
Before this condition was discovered, Napoli was originally slated to sign with the Red Sox for three years and $39 million. He ultimately settled for an incentive-laden, one-year deal worth $5 million.
On Saturday, he said he's not nervous about his situation.
"Not really," he said. "The doctor showed me that this medicine is going to work and I felt good about it and it did everything we thought it would."
Even though he's been cleared to play, he's not going to rush back.
"I'm not gonna just get out there and have a full go," he explained. "I'll progress into things. I'll increase my treadmill work, start taking ground balls and go from there."
Napoli added he's relieved the condition did not worse and he's looking forward to playing with the Red Sox.
"It's exciting," he said. "I want to get out there and do what everyone else is doing out there. I still have a long way to go. I'm going to take my time and get ready."
Red Sox general manager Ben Cherington doesn't believe Napoli will ready for the start of Grapefruit League games, but admits the first baseman/catcher is doing well and should progress quickly in his program.
"He's in good shape," Cherington said. "He's hitting, really doing everything but loading on the hip, running and things like that. The overall physical condition should allow him to move along at a good pace."
Napoli will have periodic scans on his hip during the course of the season in order to track the condition.