How would Kelly feel if he was a defensive coordinator in the league? "I would be worried," he said.
There's a lot of candidates for the conference's best signal-caller: There's 10 of them coming back, prompting several Pac-12 coaches to say it's unlike almost any situation they've seen in just about any conference.
Washington State head coach Mike Leach stretched his memory, recalling when he was coaching in the Big 12 at the same time when Sam Bradford, Colt McCoy, Graham Harrell and Robert Griffin III were all playing.
But 10 quarterbacks back? That includes six guys who ranked in the top 25 last year in total offense. It's a veritable Murderers' Row.
"We have 10 returning quarterbacks here who are all fairly impressive," he said. "I don't know that I've been around 10."
The way the Pac-12 has evolved, video-game scoring levels are the new norm. Only one team last year, Stanford, allowed fewer than 20 points per game during 2013. With the level of offensive talent returning, that will likely be the case again.
Arizona coach Rich Rodriguez, one of the few coaches who isn't returning last year's starter at quarterback, said that defense is harder than ever to coach. He joked it was the reason he's an offensive mind.
"Your goals as far as we're not going to let them get five first downs or something like that that's crazy nowadays." he said. "The offense has become too good. As a head coach you have to realize it's tougher to shut out anybody or shut people down."
Even the league's less imposing programs feature dangerous passers. California got only one win last year, but Jared Goff is one of the most prolific passers in the nation next to Mariota, Hundley, and many of the others.
Teammate Stefan McClure is glad to speak on Goff's behalf.
"I think he ranks right up there at the top of the class with all the quarterbacks coming back," McClure said. "He's got a live arm. He can throw the ball all across the field anywhere he needs to throw it. I go against him every day."
Mariota may be the top-hyped Heisman contender of all the returners, but others could sneak in the conversation. Eight Pac-12 quarterbacks are on the watch list for the Davey O'Brien Award the best quarterback in the nation which is three more nominees than any other conference.
There's a definite rivalry between them, too, which plays out in a friendly way during media days, but will flare up as they start facing each other on the field.
"It definitely motivates me," Kelly said. "I've always been the underdog my whole career. I always want to be the hardest worker out there."