Antoine was somewhat of an unknown when drafted, and spent his first two years struggling to learn how to play a position he was ill-fit for (Nickel CB). After Antoinio Cromartie was traded to the New York Jets, partially to free up one of the starting jobs for Cason, it seemed like A.J.'s pick hadn't been a bust after all.
According to Pro Football Focus, Cason was the 11th best Cornerback in the league in 2010, his first year as a starter. He was one of several contributing factors that lead to the Chargers having the #1 defense in the league that year, missing the playoffs due to spectacularly poor play by the Special Teams unit.
In 2011, hopes were high for Antoine. Many Chargers fans thought that he could be a top 10 CB. Instead, Cason seemed to struggle with maintaining focus and was bullied by physical receivers. He ended the season as the 61st best Cornerback in the league, which still made his season better than Quentin Jammer's (103rd).
2012 was a make-or-break year. Would Cason return to his 2010 form in a contract year, demanding top-dollar and taking over the #1 CB spot on the roster from Jammer? Not exactly. Jammer and Cason finished the reason as the 107th and 108th best Cornerbacks in the league, respectively. Let me remind you that there are 32 teams in the NFL, meaning that there are 64 starting Cornerbacks in the league.
The good news, and bad news, for the Chargers is that those two players are both free agents. The team can decide to move on and start over without them, but what are they chances that they could improve both CBs spots in the same offseason?
Cason is wrapping up his rookie contract, which paid him about $2.4 million per year, and that means that his price tag will go up. The last time the Chargers let a mediocre #2 CB leave (Drayton Florence) he was given $5 million a year to be a Buffalo Bill, so it's not a stretch to think that Cason could get between $3-5 million.
I always felt like the team didn't get nearly enough value out of Cason. I'm not sure if it was his fault or Jammer's, but I hated the system where Cason plays on the right side and Jammer plays on the left side. It made it too easy for teams to line up their physical receivers (who Cason struggles against and Jammer does well against) on Cason and their fast receivers (who Jammer struggles against and Cason does well against) on Jammer.
On top of that, Cason showed more than a few times that he was dangerous with the ball in his hands. Yet, the team almost never let him return punts or kicks.
My guess is that Cason will be signed by some other team that will find ways to get to ball into his hands, and will line him up against less-physical speedsters almost exclusively. I suppose that's just the pessimism talking.
In the end, I think the Chargers could get similar value from an inexpensive rookie CB than they could from re-signing Antoine Cason. As always, an improved front 7 could do wonders for the secondary.