At 35 going on 36, McCown is having a career renaissance few quarterbacks ever experience. He was in demand a year ago and will likely start again for the Cleveland Browns in 2015.
Quinn has no doubt that his career can take a similar trajectory, which is why he's in Tempe for the inaugural Veteran Combine.
"Without a doubt, I feel great," Quinn said when asked if he still envisions himself playing well into his 30s. "I'm 30, but I feel mentally as good as I've ever felt and as far as throwing the ball and understanding the game, I feel great. I had a great preseason with Seattle. I didn't get much of an opportunity in Miami, but I was 4-for-4 on the reps I got."
Quinn said he hasn't had any private workouts since being released by the Dolphins and knows that, even if he picks up interest on Sunday, he'll still have to work out with another team again in private and pass a physical.
This is why he was wavering on the process.
But Quinn decided he was tired of waiting for the phone to ring. He flew to Tempe and is staying close to the action throughout his time here. A year off has provided him with a certain perspective on how players get signed and stay in the rotation.
"I was wavering because you'd still have to go somewhere else but here, you're in front of all 32 teams," he said. "You have all the high-ranking personnel because of the owner's meetings. It's just a good chance all the way around. It's purely about passion. It's purely about my desire to play football."
Quinn, like Adam Carriker or Jamaal Anderson or Felix Jones, is going to be looked at as a player desperately trying to re-write the past. But the reality is, they're all first-round picks who didn't live up to the potential that some general manager in some organization thought they would. This isn't their fault.
That doesn't mean they can't be serviceable players in the NFL anymore.
Lump Quinn in with the pack of available backups, though, and against the competition he had on Sunday and the notion of him sticking around doesn't seem so strange anymore.
Based on the market, is it crazy to think that he's one of the more likely candidates to see the benefit of the combine and end up in a camp in a few months?
"I just feel like you've got one life to live and you should live it the way you want, and I've really enjoyed playing football," Quinn said. "It's been great for my life and my family, and I never want to look back and regret an opportunity to continue playing."