You don't even have to ask why Jaguars coach Jack Del Rio is silent about the release of Byron Leftwich.
You should already know that answer.
Byron was signed by the Pittsburgh Steelers during training camp in 2008. Byron did mop-up duty in several games during the regular season, and he even contributed to beating the Washington Redskins and the Cleveland Browns after Ben Roethlisberger was carted off in both games.
The really good reason Jack Del Rio regrets the release is because Byron Leftwich now has a Super Bowl ring.
So after all, Byron was able to prove he could contribute to a Super Bowl-caliber team. He now gets the last laugh.
My advice to you, Jack Del Rio, is the next time you have a quality QB, don't cut him. Let the guy fully heal from his injuries.