Although Trestman took his talents to the Canadian Football League after being passed over for promotion several times, he long has been respected as the one of the NFL's premier offensive strategists and quarterback gurus.
"Everything wouldn't be an overstatement," Harbaugh said Friday on WMVP-AM, via ESPN Chicago. "We use his system still of calling plays and the way he taught us those concepts and techniques. I've used (those) since I coached with the Raiders, the University of San Diego, Stanford and the 49ers."
Steve Young once compared the job of a quarterback to tending a Japanese garden because of the high level of care, time and intricacy of work that goes into a successful career. Young, Rich Gannon and Scott Mitchell all credit Trestman as the most advanced caretaker and positive influence on their development.
Asked if the Bears hit a home run with their hire of Trestman, Harbaugh responded, "Absolutely. Grand slam. That was a grand-slam hire. You see the coaches that Marc has put around him, they know football. He knows football. He's a great teacher, and I think that's coaching right there."
At age 57, Trestman has been "battered around, gotten kicked in the teeth and gone through challenges," as Seattle Seahawks coach Pete Carroll explained to the Tribune. It's refreshing to see that Bears general manager Phil Emery was willing to think outside the box enough to give Trestman a long overdue shot at an NFL head-coaching job.
Follow Chris Wesseling on Twitter @ChrisWesseling.