"Rehab, and not surgery, is expected to be enough to get Daisuke Matsuzaka's sprained right elbow healthy again, a team source said yesterday, but it might be July before he will pitch for the Red Sox.

Matsuzaka was placed on the 15-day disabled list as expected yesterday, and he won't pitch for two weeks before the club reassesses the sprain in his right elbow.

Manager Terry Francona said the chance of Matsuzaka getting the green light to throw in two weeks is "probably ambitious," adding, "I don't think we should expect him to be ready to throw then."

If it took Matsuzaka another week, that would push his timetable to approximately six weeks, which means July.

"Normally, time down, that's about what it takes to get back to the mound," said Francona. "You can kind of do the math. If a guy's down three, four weeks, and that's how long it takes to get back to mound, you're not going to get on a big-league mound real quick, you will need time to ramp up."

Exactly how Matsuzaka injured himself remains a bit of a mystery, one that may never be solved. It cropped up sometime before his last start in April, when he was pulled after just four innings against the Mariners when he suffered a drop in velocity.

After a long layoff and then a brief relief appearance, Matsuzaka made two more starts. In one against the Twins, generous run support meant he got the win despite giving up four runs in six innings. But he then allowed seven walks in 41/3 innings Monday night, when the team decided that an MRI was in order."