Buffalo ultimately elected to sign Brown to a contract following the session.
Johnson, 28, wound up signing on with the Seahawks as an undrafted free agent out of Boise State back in 2011. He spent four years in Seattle before signing a two-year, $2.5 million with the Redskins last year.
However, Washington elected to cut him loose back in March. Johnson later signed on with the Chiefs in August but was unfortunately among their final roster cuts coming out of the preseason.
In 2015, Johnson appeared in 14 games and recorded 27 tackles. Pro Football Focus has him down for playing 195 total snaps last year.