The St. Louis Rams activated cornerback Marquis Johnson from the PUP list today. He joins the active roster for the first time since a week 3 of last season. To free up space for Johnson, the Rams moved cornerback Brian Jackson to injured reserve. 

Johnson had offseason knee surgery that kept him out of training camp this year. He was placed on the PUP while recovering. He and fellow PUP listee Mark Clayton worked together while on the PUP. Clayton was not activated from the PUP this week. 

Johnson joins a cornerback group hit hard by injuries, including season enders to starters Ron Bartell and Bradley Fletcher. A second-year player, he did not see much playing time last year, but should be able to contribute. He is expected to play nickel this week. 

Brian Jackson, a second-year player most recently with the Giants, was added earlier this month, taking Bradley Fletcher's spot on the roster. He is the fourth Rams cornerback to end his season on the injured reserve list so far this year.