"It felt good," he said of his first swings since shoulder surgery late last year. "The shoulder is healthy, so it's just like normal. The only thing I had a concern with was the first couple of swings to see how it would respond. Once the first two swings felt great, I felt like taking 18 more swings."
Gonzalez will hit off of a tee for each of the next two days as well and then will have Thursday off. The Red Sox are not putting a timetable on when he'll take the next step -- live batting practice, which his teammates began Sunday -- or when he'll be ready to play in spring training games. All parties expect him to be ready for Opening Day.
Gonzalez had shoulder surgery to repair the labrum in his right (non-throwing) shoulder last Oct. 20 and was told it would be four months before he could pick up a bat, so he's right on schedule.
He said he had no reservations when he stepped into the cage.
"I didn't hold back," he said. "I took good healthy swings. I felt fine. You're waiting to see if you feel something different, but I didn't so that's a good sign."
Originally, Gonzalez was scheduled to visit with Mets physician Dr. David Altchek, who performed the surgery, on Monday. But after his team physical on Friday went well, Red Sox physician Dr. Thomas Gill spoke Sunday with Altchek and it was decided Gonzalez could begin hitting off a tee.
"I've been ready to swing; it was just a matter of getting the clearance," he said.
He's not worried about doing too much too soon.
"There's no danger right now," he said. "The first diagnosis was four months to pick up a bat, and it's been four months and a day. Medical terms is 16 weeks and I'm over 17 weeks now, so I'm on schedule."
Red Sox manager Terry Francona said he was "thrilled" that Gonzalez had been given clearance to take this step.
"He's been coming along so well, so Dr. Gill spoke with Dr. Altchek and there were no qualms about letting him proceed," Francona said.
Gonzalez played through the pain with the Padres last season, but he was still able to hit .298 with 31 homers and 101 RBIs.
"Numbers were good, so it didn't affect me numbers-wise, but it made me adjust my swing a little bit. I want to be able to get back to my normal swing," Gonzalez said. "I was in a good amount of pain, but you deal with it."
He said he felt no discomfort on Monday.
Joe McDonald covers the Red Sox and Bruins for ESPNBoston.com.