The first things you notice about Malik Jackson are his arms. They are the size of Kate Moss' waist. It's hard to believe he was once considered miscast as a defensive lineman at the University of Tennessee.

"Do they?" said Jackson, when told his biceps look bigger than last year. "I appreciate that."

His left arm tells a story of commitment and passion. It features a tattoo of his pit bull, Bruno, staring proudly as he carries weights on a yoke. Jackson's three dogs provide peace, joy and a daily reminder of loyalty to a purpose.

Jackson, whose identical twin brother, Marquis, starred at Portland State, has lived with people not knowing his name. He is driven not to be just another guy on a Broncos' defensive front that will feature the return of Von Miller and the free-agent addition of DeMarcus Ware.

"It's time to get better. It is competition. Their job is to bring in guys to create that," Jackson said. "We just have to go out there and get ourselves right and get ready to work."

Jackson's statistics are more revealing than overwhelming. Continuing his maturation from a fifth-round pick in 2012, he finished last season with 42 tackles and six sacks. It only hinted of his value. With Miller and Derek Wolfe sidelined for several games, Jackson provided power at left defensive end and consistent pressure as an interior rusher on passing downs.

His versatility should afford defensive coordinator Jack De Rio more freedom to vary his unit's looks.