PORT ST. LUCIE, Fla. -- New York Mets left-hander Johan Santana, who underwent Sept. 14 shoulder surgery to repair a torn anterior capsule in his left shoulder, has started tossing a baseball, pitching coach Dan Warthen said Friday.

Warthen said he spoke with Santana, who is rehabbing at his home in Fort Myers, Fla., by telephone. During that conversation, the ace told Warthen he has played catch three times. Santana is expected to arrive at the Mets' complex in Port St. Lucie within a couple of days, ahead of Tuesday's official reporting date.

Mets officials have estimated Santana could return in June or July, but Warthen noted Santana's injury is rare for a pitcher and he didn't want to offer any precise projection.

"We'll see what happens from there. He's played catch," said Warthen, who was retained, along with third base coach Chip Hale, from former manager Jerry Manuel's staff.

Warthen said the Mets will monitor Santana closely so that he does not attempt to do too much, too soon. The pitching coach noted Santana did not want to come out of his final game in Atlanta when he experienced the discomfort last year.

The previous season, Santana did not want to cut short his season to have his elbow cleaned out, even though the Mets were not in contention for the postseason. In 2008, Santana pitched a complete game against the Florida Marlins the second-to-last game of the regular season with the Mets' postseason aspirations at stake, despite torn knee meniscus that subsequently required surgery.

"I just don't want him, because of who he is, to push himself to try to get there too early and have another setback," Warthen said. "We knew two years ago when he had the bone chips that he wasn't ready to come out. We had to talk him into that. And even last year he wasn't going to go out in that game [against the Braves]. That's who Johan is. Common sense has to prevail somewhere."

Although Warthen said he has "no history" of dealing with players who have had surgery to repair torn anterior capsules, he added that the organization will be vigilant to ensure Santana replicates his old delivery.