Since arriving in New Orleans in 2009, Jabari Greer, No. 17 on my top 25 New Orleans Saints' players, has been arguably the most consistent defensive player. You can say this isn't much of an accomplishment considering the consistently poor play of the defense the past few years, but Greer has been the Saints' primary CB since 2009 and has generally fared well. When throwing at Greer during his four seasons with the Saints, opposing quarterbacks have averaged a 56.75% completion percentage and a 79.7 QB rating. (Stats acquired from Pro Football Focus Premium Statistics).
After four years of being the Saints' primary corner, however, Greer may very well be stripped of this title with the signing of Keenan Lewis. Lewis was brought in from Pittsburgh as the Saints' key off-season acquisition. Although he did not record an interception in 2012, Lewis led the league in pass breakups and is widely considered one of the better cover corners in the league (as examined here). Lewis outperformed Greer in 2012, but probably not by as much as you'd think. Opposing QB's had a completion percentage and QB rating of 52.7% and 80.7, respectively, when throwing at Lewis, in comparison to Greer's 58.7% and 82.4. Furthermore, Lewis (27) has father time on his side, and seemingly fits into the Saints' long term plans more so than Greer (31) does at this point in his career. Regardless, both corners will be an integral part of any type of success the Saints have this season. You can't expect to win a Super Bowl when you allow 4,681 passing yards like the saints did in 2012.