After being charged with assault following a September 2011 incident at a campus bar, the McMaster Marauders quarterback rededicated himself when he returned from a three-game suspension.
That new-found focus helped Quinlan propel his team to not only last year's Vanier Cup title, but to the cusp of winning a second championship.
"Anytime you're missing out on games, I think regardless of the circumstance, you realize how important the game really is," the fifth-year pivot said this week as the Marauders prepared to meet the Laval Rouge et Or in Friday's rematch of last year's 41-38 double-overtime victory. "Being forced to watch a game from the sidelines ... you realize how much you love being in there and how much the game really means to you.
"That's something that definitely drove me going forward all through last year, through the off-season, through this season."
The incident following a loss to Western was a watershed moment for both Quinlan and the Marauders.
The team went 3-0 without its starting quarterback and haven't looked back since, going on a record-breaking 21-game CIS winning streak that included the school's first Vanier Cup.
McMaster head coach Stefan Ptaszek says Quinlan returned from suspension with the burden of having let his teammates down. It was a feeling the product of South Woodslee, Ont., never wanted to experience again.
"He made a mistake that probably a lot of university students make in their growing up (but) he did it front of (the media) and at the expense of his entire locker-room. To have those stakes meant he was held to a higher level of accountability," Ptaszek said. "Football is not a right and I don't think most 20 year olds understand that.
"He knows it's a privilege and this may be his last football game ever and he's one of the few kids in their five years that hasn't wasted many days."
Quinlan was charged with two counts of assaulting an officer and one count of assault but eventually pleaded guilty to causing a disturbance and was given a one-year conditional sentence.
He was supported by coaches and teammates throughout the process, who said the incident was completely out of character.
"(In a) controversial situation to be involved in, to have a guy like coach Ptaszek stick his neck out there for me was saying a lot," Quinlan said. "He really backs up his talk and he truly is a players' coach and he's going to put his players before himself."
McMaster players, meanwhile, took notice of a change when their undisputed leader returned.
"He just came back with bigger passion and bigger drive than I've seen any player with in sports. It was unbelievable," Marauders receiver Robert Babic said. "You could just tell in his demeanour and his style of play. He was focused to another level and he really wanted to prove to the league and to us that he's all in."
Added defensive lineman Ben D'Aguilar: "It might have humbled him a little bit and made him work a lot harder than before to make people realize he's a good kid."
Quinlan, who was named the OUA's most valuable player in 2012 and set a conference record by completing 69 per cent of his passes for 2,457 yards, led the nation with 19 touchdowns and two interceptions.
In last week's Mitchell Bowl against Calgary, Quinlan was named MVP after throwing for 412 yards and three touchdowns while rushing for three other scores in a 45-4 whitewash of the Dinos.
Friday's championship game against Laval at Rogers Centre will be Quinlan's finale in Canadian university football. Whether or not he gets a chance to play at the next level is another question entirely.
Quinlan was invited to Hamilton Tiger-Cats training camp in 2011 and spent time with the Montreal Alouettes this pre-season before returning to McMaster.
Former Ottawa Gee-Gees quarterback Brad Sinopoli, the third-stringer for the Calgary Stampeders, was the only Canadian pivot on a CFL roster in 2012.
The reality is that quarterbacks from north of the border take longer to develop and don't count as part of the import ratio, but Ptaszek, who played in the CFL with three teams, says if anyone deserves a shot it's Quinlan.
"The CFL fundamentally has said based on their rules that they don't want Canadian quarterbacks. I would never have played receiver in the CFL ever if receivers didn't count towards the Canadian content," Ptaszek said. "I would have been cut inside five minutes but they are counted towards the Canadian content so I did get to play. Why they don't do that for the quarterback position? I don't know.
"They need to change that rule ... or one of the best players who has ever played in CIS university sport has nowhere to go from here."
Laval head coach Glen Constantin, whose team advanced to its third straight Vanier Cup with a 42-7 victory over the Acadia Axemen in last week's Uteck Bowl, has seen Quinlan up close and agrees.
"He runs to pass and not just to run to get yards. He's got a quick release, which often CFL coaches don't think of Canadian quarterbacks having," Constantin said. "I think he's been exposed to a good offensive system with good coaches. He understands structures of defences and coverages and I think he deserves a shot."
Quinlan, who is the favourite for the Hec Crighton trophy as the MVP of CIS football, desperately wants to play at the next level.
"This is a game that I've played my whole life — since Grade 7 I've been playing football," he said. "It's a game that I love and it's a game that I definitely would love to stay involved with as long as I can."
Friday's game against Laval could be his last chance to show CFL teams what he can do.
"When you play on a big stage like this, there's definitely some more eyes on you. It's different than playing just a regular-season game within the OUA or the Quebec conference," Quinlan said. "I know there's going to be eyes on me and there were last year as well."
Ptaszek says that whatever the outcome against the Rouge et Or, Quinlan's name will be mentioned along with the greats of Canadian university football.
"His five years is set in stone. Nothing he can do on Friday night ... would change anybody's opinion of what a great player he is," Ptaszek said. "He's got too much history of great football."