"Johan Santana could be one throwing session away from beginning a minor league rehab assignment.

The Mets' ace will take the mound for a bullpen session this morning at Sun Life Stadium and might be cleared by tomorrow to pitch a minor league game later in the week. He likely would pitch for Single-A St. Lucie.

Santana, recovering from surgery last Sept. 14 to repair a torn anterior capsule in his left shoulder, was in the Mets' clubhouse yesterday and repeated what he told The Post on Thursday: He hopes to pitch for the Mets this season, but isn't going to risk his future just for the sake of returning in 2011.

"I worry about being healthy, that's what I worry about," Santana said before the Mets' 8-5 loss to the Marlins last night. "If [a return this year] doesn't happen, it doesn't mean it's the end of the world.""