Bears DB Dillon Thieneman warms up during Rookie Minicamp at Halas Hall. Kamil Krzaczynski-Imagn Images | Kamil Krzaczynski-Imagn Images When you’re a connoisseur of offense like Bears coach Ben Johnson, it doesn’t take much to make a connection with guys who can bring something to that side of the football even if they haven’t been drafted. Johnson described what he like about three undrafted free agents who had caught his eye even before they took the practice field Friday for the first rookie camp workout . Of course, one of them is a tight end. Johnson knows tight ends, as a former tight ends coach. Former Iowa tight end Hayden Large built quite a reputation for as a leader of his team even without being much of a pass catcher. His blocking, special teams and overall attitude preceded him so much that Johnson even made a phone call ahead of the draft to talk to this player who wasn’t even going to be a draft pick, and even though they knew they might draft Sam Roush in Round 3.…