Johnthan Banks is a tall, lanky cornerback who is at his best as a press cornerback. With 33 7/8" arms and a 6'2" body he has a tremendous wingspan that allows him to get his hands on balls that seem out of his reach, and he used that to record a ridiculous 16 career interceptions in college. He was productive, he's a phsyical run defender with great size -- and yet, he's not a top-notch cornerback prospect.
Banks is outstanding when he's on the outside, can press cornerbacks with his lengthy arms and use the sideline as an extra defender. But he tends to struggle when he's asked to move in space, when receivers have two-way options against him and he has to react in space. He doesn't have the lateral agility to keep up with dynamic players in space, which likely limits him to a role on the outside in the NFL. There's nothing wrong with that, of course. The same goes for, for instance, Richard Sherman of the Seattle Seahawks -- and he's being touted as one of the best cornerbacks in the NFL. The limitation simply means you must cater to his positives.
This leaves little room for franchise icon Ronde Barber, however. Last season, Barber played very well as a free safety and was asked to play slot cornerback in dime packages, as well as nickel packages late in the season. But there's no room for those roles anymore. Dashon Goldson and Mark Barron are the starters at safety, and Darrelle Revis and Eric Wright are a formidable duo at cornerback. Barber's skills at cornerback have declined for years on end, and he couldn't beat out Wright barring injury.
That leaves Johnthan Banks standing in his way, but that represents another problem: they're entirely different players. Banks plays on the outside and doesn't really have the flexibility and lateral movement required to thrive in the slot. Meanwhile, Barber has lost much of the explosive athleticism that allowed him to make up for a lack of size on the outside. Banks will play outside and isn't in direct competition with Barber. Which leaves really only one option: Barber would have to be better as a slot cornerback than Banks is on the outside, which would lead to a lineup with Barber in the slot and Eric Wright and Darrelle Revis on the outside.
The chances of Barber returning to football this season grow slimmer with every passing day. The Buccaneers reportedly want him to return, but do they want to spend the cap space on a cornerback who would merely be competing for a nickel spot in training camp? And does Barber even want to come back for such a role?