23. Chad Pennington
Credit where credit is due, Pennington is a fighter. The only two-time NFL Comeback Player of the Year award winner, he knew how to overcome adversity. When it looked like his decline was final, he bounced back. At least until his last two seasons with the Miami Dolphins.
In short, they were disastrous. After starting every game in 2008, he suffered a devastating shoulder injury. He barely played over the last two years of his career as injuries ravaged his body. To sum up, it was a sad but all-too-common ending to his career.