Zack Greinke (collarbone) will begin a rehab assignment with High-A Rancho Cucamonga on Friday.

Greinke threw about 60 pitches during his most recent bullpen session on Tuesday, so he shouldn't need too long to get stretched out. Barring a setback, we should see him back in the Dodgers' rotation in a couple weeks.

The Dodgers are hopeful Zack Greinke (collarbone) can return to the rotation in two or three weeks after his successful bullpen session on Saturday.

Greinke was originally estimated to be out two months with the collarbone fracture, but he's believed to be about three weeks ahead of schedule according to Bill Shaikin of the LA Times. That timetable would put him on track to rejoin the club by the end of May.

Zack Greinke (collarbone) threw from a distance of 90 feet on Monday.

Pretty impressive considering that Greinke had surgery to repair his fractured left collarbone less than three weeks ago. "It's still a little achy here and there, but nothing worse than what you would expect, I think," said Greinke. "You try not to have setbacks but at the same time do what you can." While it's nice to hear that Greinke is making progress, he's not close to throwing from a mound and isn't expected to rejoin the Dodgers' rotation until sometime around mid-June.