Elandon Roberts knocked out with groin injury

Steelers LB Elandon Roberts left Sunday's game against the Cardinals in the first half with a groin injury and was ruled out before halftime. That doesn't bode well for his chances of being ready for Pittsburgh's Thursday night game against the Patriots. Mykal Walker took over defensive play-calling duties after Roberts and would likely lead the LB corps in playing time in any further games Roberts misses.