A busy offseason overhauling the defense isn’t yet complete, with the Chicago Bears needing to find additional pieces via the NFL draft. The question is where those pieces will fit in the puzzle. General manager Phil Emery has signed or re-signed 32 players since last season ended. Twenty have been on the defensive side of the ball, where as many as six or seven project as starters. On the line alone, Jared Allen and Lamarr Houston are expected to start at end and Jeremiah Ratliff and Nate Collins could push for starting jobs at tackle. But the Bears are expected to look for young talent to add to the mix on the line, which is why the club recently devoted one of its 30 pre-draft visits to Halas Hall on Notre Dame defensive tackle Louis Nix. Some believe the Fighting Irish product projects best as a 3-4 nose tackle, but he also could be a nose in a 4-3 defense and give the Bears a stout defender vs. the run. Nix performed last month at the Notre Dame pro day weighing 331 pounds and would strengthen a run defense that was gashed last season. The Bears allowed a league-worst 161.4 yards rushing per game in 2013 and finished with a franchise-record 2,583 yards allowed – 410 more than the next-worst team.