The Steelers will hold their final practice today, go through a walk-through tomorrow and then head to Arizona as they get ready for Sunday’s game against the Cardinals.  Center Sean Mahan returned to practice on Thursday.  Mahan is nursing a sore knee.  Hines Ward did not practice because of his sprained knee.  Cornerback Ricardo Colclough  missed practice because of a sore back.  Trai Essex missed practice with an ankle injury and tight end Matt Spaeth didn’t workout because of that bruised thigh.  The Steelers are 3-and-0 and are off to their best start since 1992.  The Cardinals are 1-and-2.  Pittsburgh leads the all-time series, 33-22-3 and won the last meeting, 28-15, at Heinz Field in 2003.  Kickoff is set for 4:15 p.m. at the University of Phoenix Stadium in Glendale, Arizona.