First off, I love the Eric Wright Trade. The 49ers were willing to give him a $7m+ a year contract in the 2012 offseason, but he opted to sign with Tampa for a lot of guaranteed money (money that was voided after the PEDs suspension). They now get him at a bargain-basement price of $1.5m for 2013...quite the steal.
Now, if you remember, all of the reporting in March 2012 was that the 49ers wanted Wright over Rogers. Based on the reporting at the Time, Trent Baalke ranked the top 3 CBs in the 2012 market in the following order:
Baalke loved Wright, and his numbers back it up. Despite having a 'poor season', wright was 14th in the NFL in +EPA/game...that's excellent. Rogers was 55th, while Brown and Culliver are tied for 74th. In 2011, his numbers were even better. He was 16th in 2011, while Rogers was 4th that year (career year).
Positive Expected Points Added (+EPA) -- The Expected Points Added attributed to a defensive player, limited to only the plays that are net positives for his team. It is a measure of a defender’s impact on the game score in terms of play-making ability. Like for +WPA, only positive plays are considered for individual defenders because very good individual defensive plays can still result in net losses in EPA. However, overall individual EPA likely correlates well with +EPA.
The 49ers Save $4.5m by cutting Rogers -- that's a huge chunk of change. We end up with a ton of free agent defensive backs after the season, but Rogers was probably going to be cut anyway. So, I think Rogers is cut. Here's the lineup if that's the case:
Slot CB (Nickel): Wright
Slot CB (Dime): Nnamdi
Additional Dime: Cox or Brock (probably Cox)
Also keep in mind that Wright is a San Francisco native and could take a home-town discount after the season...and he's only 28 this season (he turns 28 next week). Same age as Brown.