The Oakland Raiders have slowly but surely added some foundational pieces. Second-year quarterback Derek Carr has a ways to go, but he showed flashes of franchise quarterback ability last year. Rookie wide receiver Amari Cooper has the talent to be a No. 1 target in the NFL for a long time. Both are building blocks but neither has the honor of being Oakland's top overall player. No, according to ESPN Raiders reporter Bill Williamson, that honor belongs to second-year linebacker Khalil Mack.

"There are a few players in the NFL that have created as much buzz and excitement going into this season as Mack," Williamson wrote. "The No. 5 overall draft pick last year was terrific as a rookie. He was a complete player, showing ability against the run and the pass. Mack has a chance to grow into one of the NFL's best defenders quickly. One Oakland assistant coach told me Mack is 'a monster, but he doesn't know it yet.'"

 Mack was one of the best coverage linebackers in the league last season. Overall, he finished his rookie year with 75 tackles one forced fumble and four sacks. This season, new Raiders head coach Jack Del Rio is planning on unleashing Mack in the pass-rush game. As such, those around the league are expecting a breakout year from the young star linebacker as his sack numbers are sure to skyrocket.

The Raiders may not be competing for a Super Bowl any time soon. But at least they have their franchise defensive player.