So why not ask Mike Shanahan?
Trestman had a chance at the NFL combine this past spring and took advantage. Now, Cutler's having his best season in years, and the Bears are tied for the NFC North lead heading into Sunday's game against Shanahan's Washington Redskins.
How good has Cutler been?
His rating this season is 95.2, compared to 84.0 for his career coming into this season, and it's been below 90 in just one game so far. With 1,630 yards, he's on pace to throw for 4,347.
He has 12 touchdown passes and six interceptions, the best ratio of his career, and it looks like the Bears are getting the answer they wanted to one of the biggest questions coming into the season: Can Trestman get the most out of his quarterback?
So far, the answer appears to be yes.
Trestman had a few questions of his own for Shanahan, who coached Cutler in Denver. It was a short but encouraging conversation.
"We talked in generalities, and basically Mike said, 'You're really going to enjoy working with Jay. He's a smart guy, he wants to work, he wants to learn. He's coachable,'" Trestman said. "It wasn't a long conversation, but it was reassuring to hear it from him.
Shanahan said his experience was "nothing but positive."
"I'm a big fan of Jay Cutler's," he added.
Shanahan was Denver's coach when the Broncos drafted Cutler out Vanderbilt with the 11th pick in 2006, and the quarterback with the rifle arm put up the biggest numbers of his career under him.
After starting five games as a rookie, he threw for 3,497 yards in 2007 and topped that the following year by throwing for 4,526.
Then, Shanahan got fired. Cutler clashed with new coach Josh McDaniels and wound up getting traded to Chicago before the 2009 season.
With the Bears, it hasn't been the smoothest ride. There were issues with the supporting cast, particularly when it came to protection, and big questions over whether he is actually coachable.
Besides the feud with McDaniels, Cutler didn't exactly mesh with past Bears offensive coordinators Ron Turner, Mike Martz and Mike Tice. He even got up and walked away when Tice took a seat next to him and began talking during a game against Dallas last season. Two weeks earlier, he shoved offensive lineman J'Marcus Webb after some poor blocking, incidents that didn't exactly help his image.
The Bears hired the offensive-minded Trestman to replace Lovie Smith, hoping he could get through to their talented quarterback.
So far, it looks like he is.
"Him and Mike have a lot of similarities," Cutler said. "They like to really protect the quarterback. A lot of stuff that we do offensively is to make sure that we're successful and can complete a pass and we're protected."
The biggest difference Shanahan sees now is the supporting cast.
They added a go-to receiver a year ago when they reunited Cutler with Brandon Marshall, and Alshon Jeffery is paying off in a big way this season after being taken in the second round in 2012. The offseason addition of tight end Martellus Bennett gave Cutler another big target, and with four new starters on an overhauled line, Cutler isn't running for his life the way he did in recent years.
The ball is also coming out of his hands quicker, which takes some pressure off his blockers. And when Shanahan looks at Cutler now, he sees more than a familiar face. He sees a familiar result.
"That's the way he played for me," Shanahan said.
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