In each level you jump up, football gets faster. There's a huge change in the speed of the game from middle school to high school, from high school to college, and from college to the NFL. Adjusting to that new speed is something rookies always struggle with during their first pro training camp. Even though he's now a six-time Pro Bowler, Clay Matthews III found he was woefully unprepared for the NFL pace during his first preseason game in 2009.
"I was going up against [Vince Young]," Matthews told Packers.com. "Vince Young, like a 12-play drive, no huddle, I was gassed, I didn't think I was going to make it very long in this league." Six Pro Bowl selections later, it's safe to say Matthews adjusted pretty quickly.