Minnesota parted ways with Griffin earlier in the year, before free agency began on March 13. He was due a $4.1 million salary this season. The Vikings opted to save the cap room by Griffin and veterans such as guard Steve Hutchinson.
Griffin started 14 games last season for the Vikings. He missed all but two the year before with a knee injury. Griffin was a second-round pick in 2006.
The Vikings are expected to be seeking cornerback help in the draft this year.
Washington still has DeAngelo Hall and Josh Wilson as its top two corners, so they might view Griffin merely as depth at the position.