Three cornerbacks with one NFL start between them will vie to start opposite Ike Taylor in Pittsburgh. Fourth-year pro Keenan Lewis, the eldest of the group at 26, and second-year defenders Cortez Allen and Curtis Brown, both 23, are the most likely candidates to start at left cornerback after William Gay signed with Arizona. “It’s going to be interesting,” Steelers defensive coordinator Dick LeBeau said last week of the competition. “It will probably go on into training camp and some actual game competition before that sorts itself out. I feel good about what I’ve seen here so far.” Lewis received his most extensive playing time in 2011, notching 37 tackles, defending six passes and hauling in his first career interception in 16 games (one start). He likely rates an early edge, the way we hear it, but Allen and Brown have shown potential early in their Steelers careers.