Bengals sign CB Jason Allen, retain S Nelson

CINCINNATI (AP) - The Bengals have signed free agent cornerback Jason Allen from Houston and agreed to a four-year deal with safety Reggie Nelson, who was one of their unrestricted free agents.

The moves on Monday bolster a secondary that was one of their main concerns in the offseason. Top cornerback Leon Hall is recovering from a torn left Achilles tendon.

Allen played in all 18 games for the Texans and their first-round playoff victory over Cincinnati, getting four interceptions overall last season. He was a Dolphins first-round pick in 2006 and joined the Texans last season.

Nelson started every game for the Bengals last season and led the team with four interceptions. He's entering his third season with Cincinnati.