Why Haven't the San Diego Chargers Replaced the Training Staff?

I know I wrote about this back when Norv Turner and A.J. Smith were both officially kept on board for the 2012 San Diego Chargers season, but why hasn't the team training staff been fired and replace yet?

If the basis behind keeping Norv and A.J. was "The 2011 team was dealing with too many injuries to compete" and the basis behind keeping them in 2010 was "The team was dealing with too many injuries to compete", the logical conclusion is that they are doing a poor job of keeping the team healthy (and/or getting players healed and back on the field in a timely matter) and need to be replaced.

Not only does the team's head physician, Dr. David Chao, have quite the reputation as a bad person and a bad doctor, but the team is now dealing with the fallout of Kris Dielman's retirement after a seizure that may or may not have been caused by him continuing to play in a game after being concussed. Many are wondering how the team doctors, of which Chao has the most authority, could've missed Dielman's obvious symptoms when they were obvious to referees, other teammates, fans watching on television and the tv commentators.

There is zero reason to keep Chao and his medical/training staff in San Diego. The team is constantly riddled with injury (Buster Davis and Larry English, anyone?) and now has one of the worst reputations in the league of taking care of their own players. Not only would a new training staff possibly convince free agents to sign with the team, but it could only improve the Chargers' chances of fielding a healthy team.