Richard Marshall chooses the Chargers

AP

As the Chargers try to close the broad gap between themselves and the Broncos in the AFC West, they’d added a defensive back who only recently became available.

Per a league source, former Dolphins cornerback Richard Marshall has agreed to terms on a one-year deal with the Chargers.

The Jaguars also were in the mix to sign Marshall, who collected $6.1 million for a total of four games with the Dolphins.

Marshall also has played for the Cardinals and Panthers.  In San Diego, he joins a depth chart currently topped by Shareece Wright and Derek Cox, with Johnny Patrick and Steve Williams as the primary backups.