Johnson announced his retirement Sunday, David Furones of the South Florida Sun Sentinel reports.

Johnson reverted to Buffalo's practice squad Monday, per the NFL's transaction log.

Buffalo elevated Johnson from its practice squad to the active roster Saturday ahead of Sunday's game versus the Vikings, Field Yates of ESPN reports.

The Bills signed Johnson to their practice squad Wednesday, Alec White of the team's official site reports.

Johnson rushed six times for 20 yards and caught one of two targets for two yards during Buffalo's preseason loss to Carolina on Friday.

Johnson worked with the wide receivers in practice Thursday to improve his route running and footwork, Joe Buscaglia of The Athletic reports.

Johnson rushed seven times for 49 yards and brought in two of three targets for 16 yards in the Dolphins' 34-3 loss to the Titans on Sunday.

Johnson rushed 13 times for 39 yards in Monday night's 20-3 win over the Saints.

Johnson was signed to Miami's active roster Monday, after running for 102 yards and two touchdowns Sunday against the Jets following a call-up from the practice squad, Adam Schefter of ESPN reports.