In need of a defensive differencemaker, the Broncos are in pursuit of arguably the most talented pass rusher in the NFL. Von Miller, circa 2012. "He's got to put last year behind him, and hopefully he learned his lesson from last year," general manager John Elway said at the NFL scouting combine. "Hopefully, he gets back to playing football and being the Von that he can be." Miller had 18½ sacks in 2012, his second NFL season. He had only five sacks in 2013, when he was suspended the first six games for violating the NFL drug policy and suffered a torn anterior cruciate ligament in his right knee during Game 15 at Houston. There is no free agent the Broncos can acquire, or player they can draft, who would have more impact on their 2014 team than a return to form by Miller. "Your hope is there is a maturation and growth and improvement that's with any player, year to year," said coach John Fox. "We've got a lot of resources, a lot of people working very hard whether medically, spiritually, whatever in that building." Does he get the sense that Miller has matured? "You always get that sense with him," Fox said. "He's a good kid. But sometimes, at least in the past, some things have cropped up (laughs). That's why you hope he's moved forward." Old men in the middle. The Broncos' starting linebacker the past two seasons was a combined 73 years old: Keith Brooking was 37 in 2012, and Paris Lenon was 36 last season. So it would make sense for Denver to get younger at that position. Problem is, middle linebacker has dropped down the list of position priorities in the NFL because that player now is smaller to play in pass coverage or comes off the field in pass situations.