ENGLEWOOD, Colo. — University of Buffalo linebacker Red Murdock was starting to wonder if he’d get drafted at all when the Denver Broncos made him “Mr. Irrelevant” as the 257th and final pick of the NFL draft on Saturday. “The thoughts crept in, but I was trying to keep my mind off of things that I can’t control,” Murdock said in a conference call with reporters at team headquarters in suburban Denver. “And when I got that call, I was extremely grateful.” So was Utah tight end Dallen Bentley,