Carlos Beltran underwent surgery on his right knee on January 13th. That much we know; the extent of the surgery is not completely known (what has been reported is that numerous bone fragments were taken out of his knee, and that it was a "clean up" procedure).
We heard reports all spring training about how hard he is working, spending three hours a day in the weight room with the team's medical staff etc., which is great. I have no doubts that Carlos Beltran is one of the hardest workers on the team, and is eager to return to baseball.
However, it was originally reported that he was supposed to begin running today, and that would "start the clock" on the 4-6 week time-table to return to the Mets and performing baseball activities. However, yesterday the news came out that he is not running tomorrow, but that he also has not had a set back. Whether or not the first report (which was not from a team's beat reporter, but a national reporter, Will Carrol at Baseball Prospectus) was just poor information, or a guess, we don't know.
What we do know, it is now 12 1/2 weeks from the surgery, and it will be 3 months on Tuesday. That is a long time following a "simple clean-up surgery". Whatever the extent of the surgery that was performed, hopefully Carlos will begin running pain-free soon, and start patrolling center field in Citi Field before June 1.