The Arizona Cardinals have placed running back Chris Johnson on injured reserve with a designation to return, meaning he will eligible to return for Super Bowl 50, the team announced Tuesday.

Johnson was given a timetable for a return of six-to-eight weeks due to a fractured tibia, but with this designation he will now have to wait the full eight weeks to make his return, if the Cardinals make it that far into the postseason.

The 30-year-old will be eligible to return to practice in six weeks.

It's a blow to both Johnson, and the Cardinals. The running back is in the midst of a comeback season, having regained the form from earlier in his career when he was considered one of the best backs in the league.

With Johnson sidelined, the Cardinals will likely turn to Andre Ellington to become the starter after he recovers from toe injury that could sideline him Sunday. Rookie David Johnson is likely to get significant carries for the remainder of the season as well.

The Cardinals also promoted Kerwynn Williams from their practice squad to bolster the depth at the running back position.

Johnson had 814 rushing yards and three touchdowns on 196 carries this season.