Richardson totaled three solo tackles, a sack, two tackles for loss and a pass defensed in Thursday's 36-28 win over the Steelers.
Richardson had one total tackle and one QB hurry in Sunday's overtime loss to the Bengals.
The Vikings have signed Richardson to a one-year, $3.6 million deal, Tom Pelissero of NFL Network reports.
Richardson had three tackles and one pass defensed in Sunday's 22-17 playoff loss to the Chiefs.
Richardson (neck) is active for Sunday's wild-card game in Pittsburgh, Andrew Gribble of the Browns' official site reports.
Richardson (neck) is questionable for Sunday's wild-card game against the Steelers, Jake Trotter of ESPN.com reports.
Richardson had a team-high 10 tackles and blocked two kicks in Sunday's 23-16 loss to the Browns.
Richardson (neck) is active for Sunday's game versus the Jets, Andrew Gribble of the Browns' official site reports.
Richardson (neck) is officially questionable for Sunday's game against the Jets, Scott Petrak of the Elyria Chronicle-Telegram reports.
Richardson (neck) is expected to be active for Sunday's game against the Jets, Nate Ulrich of the Akron Beacon Journal reports.