"Chicago Cubs pitcher Kerry Wood, who is already rehabbing from shoulder surgery, will undergo arthroscopic surgery on his right knee Tuesday to repair a medial meniscus tear," reports MLB.com's Carrie Muskat. There's no indication in the article, or the AP's shorter version, about the cause of the tear or when the tear was discovered. Muskat states that Wood "might have been ready in late April for the season" but that the "knee surgery will set him back a couple weeks." Wood threw in the bullpen today and will do so again on Monday, as the knee isn't bothering his pitching, but he won't be back to throwing long toss until at least a week after the surgery, according to Jim Hendry.

This seems to me to mean that Wood will have very limited opportunities to pitch in spring training games, if at all, and that he will have to throw 1 or 2 rehab starts in the minors before joining the team.