If Steelers quarterback Ben Roethlisberger has enough time to set up and throw the ball on Sunday night in Jacksonville, he might have his way with the Jags’ secondary. Two of the three starters haven’t practiced yet this week, and a third has been limited due to injury. Safety Reggie Nelson (knee) and cornerback Drayton Florence (groin) might not play on Sunday after missing practice for a second straight day on Thursday. Both missed most of the Jags’ Week Four game against the Texans, and Jacksonville gave up more than 300 yards through the air to Houston. Cornerback Rashean Mathis was limited in practice on Thursday with a bruised shin that he sustained against the Texans. If Nelson and Florence can’t go, Pierson Prioleau and Will James will get the nod.