I've been seeing reports on the internet today that Jose Contreras has some sort of injury, but have seen/heard no confirmation from solid sources. That all changed a minute ago when Bruce Levine from ESPN 1000 reported that Jose complained about some hip pain following a side session this weekend.
The White Sox have sent him for an MRI, and even though no results have been announced, they're making arrangements to have his rotation spot filled. There was some confusion as to whether the issue is a hip, back, or both, but it sounds like he is indeed headed to the DL for a bit.
Charlie Haeger, for those who don't know, is a young knuckleballer who actually retired from baseball after he was unsuccessful as a "normal" pitcher. In his year away from the game, he developed his knuckleball, and the White Sox welcomed him back to their organization. Since then, he's steadily risen through the system to the point where, other than Brandon McCarthy, he's the prospect who is currently closest to major league ready.
Haeger was given a number of starts, with ominous results, in spring training while Freddy Garcia and Javier Vazquez were playing in the WBC. Once Haeger left the thin air of Arizona, however, he has pitched very well, including a game against a major league line-up. He's been nothing short of amazing this season in Charlote, leading the International League in IP and ERA.
My understanding as to why the White Sox are choosing to go with Haeger over McCarthy is that Brandon threw on back-to-back days for the first time in his career this weekend. McCarthy is not stretched out, nor would he have the required rest to get ready for a spot in the rotation.
Update [2006-5-8 21:22:51 by The Cheat]: Dave Van Dyck of the Chicago Tribune tracked down the first quotes from White Sox staff.