The Texans signed Johnson to a contract Wednesday.
The re-signing of Johnson, who previously served as a third-string quarterback for Houston for two weeks in November before being released, suggests the team isn't confident backup signal caller Taylor Heinicke (concussion) will be available for the regular-season finale in Indianapolis. If that's the case, Johnson would be active for the first time all season as the No. 2 quarterback behind starter T.J. Yates.