A week ago, Red Sox manager Terry Francona said that injured starter Daisuke Matsuzaka would not need to undergo Tommy John surgery. Earlier on Wednesday, Francona said that nothing had changed, and that the rehab plan remained the same. So you can see how this comes as a pretty substantial surprise:

Source: Matsuzaka leaning toward TJ surgery after Yocum found significant tear and recommended procedure. DM to discuss with Red Sox.

Matsuzaka's elbow sprain was re-evaluated by Dr. Lewis Yocum, and Yocum reportedly found sufficient damage to recommend surgery, meaning the tear in Matsuzaka's ligament is bad, if not complete.

So now Matsuzaka and the Red Sox will consider their options, but if Matsuzaka's ligament tear is as significant as it sounds, there's not a whole lot they can do. You can't really rehab a badly torn UCL.

If Matsuzaka does undergo Tommy John surgery, he'll be done for the rest of 2011 and much of 2012. If he doesn't, he'll take a rest-and-rehabilitation approach, but that could keep him out for a very long time even if it worked, and it wouldn't be guaranteed to work. A ligament replacement procedure appears likely.