After suffering a rib injury against the Saints in mid November, 49ers cornerback Tarell Brown returned to action this past Sunday against Tampa Bay.Brown, the starting right cornerback before his injury, played as the extra corner in the nickel defensive package, on the left side, and was in on 71 percent of the defensive snaps because the Bucs trailed early.The bad news for Brown is that former nickel corner Tramaine Brock has claimed his former starting spot at right corner. The good news for the 49ers is that the team's cornerback corps is now as talented and deep as it's been in the three years since Jim Harbaugh became head coach.Over the past four games in the 49ers' consecutive victories over the Rams, Redskins, Seahawks and Bucs, San Francisco's defense has been playing at a high level, and the play of the cornerbacks has been a big factor. Brock and Carlos Rogers now work as the starting tandem, with Brown as the nickel back and veteran Eric Wright – the former Buc picked up this season – as the fourth corner.Wright, 28, is a former starter in Cleveland, Detroit and Tampa Bay, and has been active for the 49ers' past six games. Over that span he has an...