5. Dustin Johnson
Perhaps the most surprising storyline coming into PGA Championship week is just how little buzz surrounds the top-ranked player in the world, Dustin Johnson. The man who ripped the mantle away from the aforementioned Thomas and Matsuyama earlier this season has been trying to play himself back into form since the bizarre injury he sustained at the Masters.
Since missing the cut at the U.S. Open, DJ has been trending in the right direction with a T8 and T17 in his last two starts. In a year that looked like it would be a multiple major season for Johnson, the PGA is his last shot to pick up major No. 2.