Culliver's torn ACL part of ominous week

SANTA CLARA, Calif. -- The San Francisco 49ers were seeking cornerback options when they nearly acquired veteran Eric Wright from Tampa Bay.

Their need at the position has only grown since Wright's failure of a physical exam scuttled an agreed-upon trade, precipitating Wright's release from the Buccaneers.

News that the 49ers lost third corner Chris Culliver to a torn ACL in his left knee Thursday will force shuffling in the secondary, at least. It also highlights the role injuries can play in diminishing a team's chances. The 49ers have already lost starting receiver Michael Crabtree to a torn Achilles tendon. Top linebacker Patrick Willis recently suffered a broken hand, an injury he has played through in the past. Elsewhere in the NFC West, the rival Seattle Seahawks are moving forward without wide receiver Percy Harvin, perhaps for most or all of the season.

Culliver was not one of the 49ers' best players, but he gave them a welcome option at a position San Francisco already needed to address in the coming year.

Fellow corners Tarell Brown, Nnamdi Asomugha and Tramaine Brock are signed through the 2013 season only. Carlos Rogers' salary is set to climb in 2014, amplifying questions about his future with the team.

Brock and Asomugha become leading candidates to play the snaps Culliver would have played on the perimeter in the nickel defense. Asomugha impressed in practice Thursday, but Brock remained ahead of him for now. Perrish Cox provides another option behind Brown and Rogers, the incumbent starters.