If Ellis Lankster ever developed into a shutdown corner, he would have one of the coolest nicknames ever, Ellis Island. In 2012 the project had a bit of an up and down season. Darrelle Revis' injury gave him ample playing time. Lankster's performance tended to depend on where he lined up.
Lankster really struggled playing in the slot. He allowed 8 catches in just 43 plays defending the slot. Those catches averaged over 11 yards per pop. On the outside, he allowed one catch per every 11.5 plays covering. Kyle Wilson was at a completion every 11.7 plays. Antonio Cromartie was at 13.2.
Lankster will be 26 by the time 2013 starts. That is getting old for a "potential" type player. He did flash some ability in 2012, but a backup level player needs to be versatile. If Lankster wants to stick in the NFL, he needs to get better playing the slot in a hurry.
I don't see a problem in having him back in camp for one last shot, but this should be his last shot. If he doesn't improve, his spot can better go to somebody younger with more upside.