Rory McIlroy, the favorite to win the 2011 PGA Championship, suffered an awkward injury to his hand while trying to escape the trees on Atlanta Athletic Club's hole No. 4. Check the video here -- you can see he gives a rather full swing to a ball that's planted right behind a tree root.
His 7-iron strikes the root, causing him to let it bend and fly away as he looks down at the root, then at his hands. It appears to be a wrist injury, based on how he's holding it and showing it to concerned onlookers.
He's attempting to play on, perhaps just to test his wrist. It's not certain yet whether he'll withdraw, but it's hard to imagine he could put together a solid first round with an injured wrist. We'll update once word becomes available either way.