Coulter was signed to the Cardinals' practice squad Wednesday, Darren Urban of the Cardinals' official site reports.
With DeAndre Hopkins (knee) and Robbie Anderson (back) both questionable to play Sunday versus the 49ers, Coulter could have an opportunity for elevation to the active roster in Week 18. The wide receiver has yet to play in a game this season, and if he does end up being active for Sunday's regular season finale, he'll likely have little to no impact on the offensive game plan.