Ziggy Ansah sat down on a stool in front of his locker after practice today, grabbed the walking boot on floor and strapped it around his sprained left ankle. Ansah declined to answer questions about the injury he suffered two weeks ago, in a 31-30 win over the Dallas Cowboys, but the Detroit Lions added some insurance today in case Ansah can’t play Sunday against the Chicago Bears at Soldier Field. Defensive end Austen Lane, who had three sacks in three seasons with the Jacksonville Jaguars and was waived by the Kansas City Chiefs in August, signed a one-year deal to help the Lions’ depleted pass rush. Starting left end Jason Jones was lost for the season with a torn patellar tendon in September, and defensive tackle Nick Fairley hasn’t looked like himself since suffering a shoulder injury in Week 1. Defensive tackle C.J. Mosley, who played with Lane in Jacksonville, said the 6-foot-5 defensive end looked ready to contribute when he saw him in the locker room today. “Austen is what we are all about already,” Mosley said. “He’s got to come in and pick up where we’re already at and catch up with the rest of the guys, but as far as the type of person he is, real cool dude, and you know he’s going to ride when it’s time to ride on the field.”