Fort Myers, Fla. - Adrian Gonzalez hit Monday for the first time since shoulder surgery four months ago and is confident he'll be ready for opening day.

Boston's new first baseman received medical clearance on Sunday to begin swinging and said he hit 20 balls off a tee. He's scheduled to hit off a tee for two more days, then take a day off for his condition to be reassessed.

"The only thing that I had any concerns with were the first couple of swings, see how it responded," Gonzalez said, "and once the first two swings felt great, it was just like taking 18 more swings."

Gonzalez hurt his right, non-throwing, shoulder last May and still played 160 games for the San Diego Padres. He underwent surgery on his labrum on Oct. 20 and was traded to the Red Sox on Dec. 5 for right-hander Casey Kelly, two other prospects and infielder-outfielder Eric Patterson.

The additions of Gonzalez and left fielder Carl Crawford improve an already strong batting order that includes Dustin Pedroia, Kevin Youkilis, David Ortiz and Jacoby Ellsbury. Barring injury, all six should be in the starting lineup for the opener against the Texas Rangers on April 1.

"It looks like he was getting a little bored not being able to hit, so it'll be fun and fun for all of us to have him out there and hit with us," Youkilis said. "We don't want him to come out right away. We would rather him just slowly progress and get to the point where he's 100 percent healthy and helping us on April 1, not March 1."

Despite pain from the injury, Gonzalez batted .298 with 31 homers and 101 RBIs and missed just two games last season. He hit 36 homers in 2008 and 40 in 2009.

The injury "didn't really affect me numbers-wise, but it made me adjust my swing a little bit," he said. "So I wanted to go and be able to get back to my normal swing. I was in a good amount of pain. You deal with it."

Gonzalez missed just 11 games in his five seasons with San Diego, batting .287 and averaging 32 homers and 100 RBIs while winning two Gold Gloves.

He said he's been ready to swing for some time but had to get the medical OK.

"He was kind of champing at the bit," manager Terry Francona said.

The go-ahead came after Red Sox team physician Dr. Thomas Gill spoke Sunday with New York Mets medical director Dr. David Altchek, who operated.

"They say four months to start swinging, and today is four months plus a day," Gonzalez said, "so I'm on schedule."

Besides, he usually doesn't swing a bat before arriving at spring training anyway.

"I didn't hold back. I took good, healthy swings and I felt fine," he said. "Shoulder's healthy, so it's just like normal."