The Cardinals wanted to bring in Evan Mathis to give them a veteran guard and leadership next to right tackle D.J. Humphries.
That hope has been dashed five games into the season.
Mathis, who had already dealt with foot and toe injuries this season, suffered a season-ending ankle injury Thursday night in San Francisco. The Cardinals put Mathis on injured reserve Saturday.
To replace him on the roster, the Cardinals signed tackle Ulrick John from the Dolphins’ practice squad.
Earl Watford is expected to replace Mathis in the lineup, as he did against the 49ers and earlier this season when Mathis missed a game against Buffalo.