ENGLEWOOD, Colo. — DeMarcus Walker trudged off the practice field sporting an altered physique and a tone of excitement. It was mid-June and another day of OTAs had ended. Walker could only look ahead to what he believed would be his breakout season.



After switching from outside linebacker to his usual defensive end position, regaining the 40-some pounds he lost and spending an offseason geared toward a comeback, Walker had the fortitude of a player on the brink of something big.



But the past four months haven’t gone at all as he planned. The former second-round pick, whom general manager John Elway once praised for his college production and his ability to play inside and out, has been inactive for the majority of his sophomore season in the NFL.



Walker didn’t see the field until Week 7, in a blowout win over the Cardinals in Phoenix. He suited up for the next two games and was credited with a sack against Houston. But then he went back to...