Seems like a steroid story to me. Great success followed by massive dropoff and injury problems. I remember pre-Boston storyline that he was a workout freak and had an amazing gym routine. That is always the steroid cover story (See Clemens, Roger). Add to it that the stuff can make you psycho.
If he'd stayed in Tampa next to all the drug clinics he might have been fine, but the Rays knew and didn't want the risk. Once he came to the much less drug friendly confines of Fenway Park* without his chemicals everything fell to pieces. He'll be out of baseball in 2-3 years.
Sorry I'm trolling. Seriously no team is different than any other. Not serious, its more likely the opposite as it is logical that players on constant contenders are more likely to use drugs. All pro athletes cheat if they can. Sox, Yankees doesn't matter. Seriously I'm kidding about this.