Kerry Wood leaves game

Well yesterday, Kerry Wood left his start after just 2 innings when his shoulder became sore. He has said that it wasn’t hurting and was just trying to err on the side of caution. Hopefully Kerry is right and there is nothing wrong with him because losing him right now would be a major blow to the Cubs. Kerry said his tricep injury last year was more pain, today was tightness in the shoulder.
Another reason this worries me is that Mark Prior (though he makes his debut today) has yet to pitch in a preseason game. The reason the Cubs are giving is that they are building up his arm in simulation games, which according to them is a very controlled environment and very little chance of him getting an early injury. While I hope they are telling us the truth, after last season debacle it is hard to believe anything the Cubs brass has to say about injuries or preventing them.