At one point, Beltran believed he'd resume running by mid-April.
"That's kind of unfortunate," Mets manager Jerry Manuel said. "What we have to do is we have to continue to play the way we have in the last three or four games and hope that Carlos begins to recover quickly. I mean, he's obviously an integral part."
Beltran was examined in Vail, Colo., on Tuesday by the doctor who performed his surgery in January. His return by mid-May, once considered likely by the club, now seems less likely.