Driven to succeed: Khalil Mack relentless is quest to reach another level

Ashlee Rezin/Sun-Times Bears linebacker Khalil Mack said the transition from Vic Fangio to Chuck Pagano as defensive coordinator has been “effortless. That’s all you can ask for.”BOURBONNAIS — Before he came to the Bears, Khalil Mack was known mostly superficially in Chicago — a dominant player seen through highlights, an occasional televised game and a resume that included four Pro Bowl selections and the 2016 AP Defensive Player of the Year Award.

As it turns out, he was much more than even that impressive standing with those lofty credentials. Mack’s presence invigorated the entire team from the moment he arrived, and his work ethic raised the bar for the Bears’ defense. Like Julius…