Bush signed with the Cardinals on Tuesday, Darren Urban of the team's official site reports. The Cardinals' continued search for a short-yardage back has yielded Bush, who didn't participate in training camp and has yet to play this season. The six-year veteran suited up for the Bears in the previous two campaigns, earning 177 carries for 608 yards (3.4 YPC) and eight touchdowns. Since no other RB in Arizona has emerged as a consistent goal-line threat, Bush could be the guy behind clear-cut No. 1 Andre Ellington.