Johnson, 28, will be joining his fourth team in his NFL career after stints with the Pittsburgh Steelers, Carolina Panthers, and the Baltimore Ravens.
Houston's wide receiver room has been depleted this season after season-ending injuries to some of its stars, Tank Dell (dislocated kneecap and torn ACL) and Stefon Diggs (torn ACL).
SEE ALSO: Texans' star Tank Dell done for season after dislocating knee, tearing ACL, head coach says
Coming off a loss to the Kansas City Chiefs on Saturday, the Texans will play the Ravens on Christmas Day.