Mention Tony Sparano, and the eyes come to mind. More specifically, it's the sunglasses. Day or night, inside or out, they're providing persistent shade while casting the cool yet combustible 54-year-old as a perfect big-screen wise guy to protect Michael Corleone's blind side.

So, at the risk of being strangled with a piano wire, we ask, "Hey, Tony, what's up with the sunglasses?"

"It's a great story," says the new Vikings offensive line coach, whose eyes are being entrusted to redefine, redevelop and rejuvenate the team's weakest unit as training camp opens on Friday in Mankato. "And I'm glad you're asking that question so I don't get beat up in Minnesota."

Stand down, Upper Midwesterners. The East Coaster from West Haven, Conn., isn't being arrogant, self-centered, intimidating or rude by wearing sunglasses at traditionally inappropriate times. He's simply protecting eyes he nearly lost 38 years ago.

"I was 16 years old working at a pretty popular fast-food restaurant," Sparano said. "I was playing high school baseball [at New Haven Lee], so I was working the night shift from midnight to 6 a.m. on Fridays and Saturdays.

"I'd change the hot-oil vats for the next day. I'd pump the oil out of the vats, through a hose and into a filter that cleans the oil and puts it back in."

Tony Sparano gave instructions during a workout, and not quietly. Center John Sullivan said he expects “a big change in terms of how much we get yelled at.”

When the hose isn't properly cleaned, the leftover oil inside hardens, creating a dangerous clogging situation. Sparano learned that the frightening way on a Friday night when he didn't check the hose before sticking it in hot oil and flipping on the pump switch.

"I turned away and heard this big, loud, grinding noise," Sparano said. "As soon as I turned back to see what it was, the hose popped off the joint and all that hot oil hit me right in the eyes."

5,052-pound hot seat

Today, the veteran NFL coach oversees the Vikings' No. 1 priority from atop a giant hot seat primed to unleash 16 linemen and 5,052 pounds of humanity into the Battle Royale of NFL training camp competitions. Seven of the combatants have started at least 50 NFL games. Eleven have at least one start.

"I think Tony's importance is huge because he's come in with a totally clean slate," Vikings General Manager Rick Spielman said. "It's great to have a different set of eyes and a new sense of urgency and expectations that he's put on everybody.

"Our whole point this offseason, at all positions but especially the offensive line, was to create as much competition as possible. These guys all pushing each other is going to be the most interesting position battle to follow in training camp."

In the middle of it all will be a shorter, older, louder fellow who's still reminded nearly four decades later not to take eyesight for granted.

"You can see there's still a scar on my face," said Sparano, taking off his glasses. "I had a patch over my left eye for 22 days, a patch over my right eye for 14. The left eye never did get right. The cornea is burnt and sun-sensitive, light-sensitive.

"I hear people always say, 'Why does he have these sunglasses on at a night game?' Or, 'Why is he wearing them inside?' Hey, it's that kind of bright light that causes my eyes to start running, tearing and crying.

"So that's the story. Indoors or not, if the lights are on, the sunglasses are on."

Won't lose his marbles

Sparano was born Oct. 7, 1961. He was the typical kid. Enjoyed the outdoors. Played multiple sports. Meticulously organized his marbles …

Wait. What?

"Yeah, I organized my marbles," Sparano said. "By color, shape within the marble, stuff like that. Being organized isn't something I take lightly."

Weird. But good foreshadowing for an NFL coach, particularly an offensive line coach hamstrung by the many practice restrictions of the modern NFL collective bargaining agreement.

"He organized his marbles?" said center Joe Berger, who has played under Sparano in Dallas, Miami and now the Vikings. "I'd say that fits based on how organized he is now."

The opening for Sparano in Minnesota was created a day after last season when coach Mike Zimmer fired Jeff Davidson. Asked why he didn't keep Davidson, Zimmer aimed straight and delivered five Parcellsian words that said it all: "Because I didn't want to."

Davidson had survived Zimmer's purging of Leslie Frazier's staff in 2014, but their coaching styles proved to be too dissimilar. Zimmer openly questioned the linemen's mental toughness and acknowledged the unit's most obvious production deficiencies when he said quarterback Teddy Bridgewater was "running for his life" during a season in which he was sacked 44 times and pressured more than any other NFL quarterback, according to Pro Football Focus.

"I don't really want to talk about what was lacking," Zimmer said. "I know Tony. We worked together in Dallas [2003-06]. Tony's a fiery guy who pays close attention to detail and will push the guys. The mentality that he has, he's kind of similar to me in a lot of ways. He's aggressive. He's not afraid to coach them hard.

"If you talk to any of our offensive linemen, they'll tell you the mentality is different. They're not standing around. They're busting their rear ends. Tony makes them study. He was giving them written tests. In the spring."

Fruits of Parcells tree

Their expertise rests on opposite sides of the ball, but Zimmer and Sparano share a special bond that four words can describe.

"He's a Parcells guy," each said of the other.

Bill Parcells was a direct, tough-love visionary who became a Hall of Fame example of the notion that NFL players absorb the personality of their coaches.

"I think inherently all football players are tough," Zimmer said. "As a coach, the more that you talk tough, act tough, be tough, players start to develop the personality of the coach. … Tony can bring that to the offensive line."

When Parcells arrived in Dallas in 2003, he kept Zimmer as his defensive coordinator and hired Sparano as his tight ends coach. In 2008, when Parcells was running the Dolphins front office, he hired Sparano as head coach. Sparano set the NFL record for biggest one-year turnaround, taking a team that went 1-15 under Cam Cameron and going 11-5 to win the AFC East.

Of course, Sparano has spent a lot of time on the other side of the NFL's firing squad. He's been let go by Cleveland, Washington, Jacksonville, Miami, the Jets, Oakland and San Francisco. Last year's stint as 49ers tight ends coach marked the fifth time in 17 seasons he has been part of a coaching staff purge after only one or two seasons.

"Minnesota has a lot of good people all pulling in the right direction," Sparano said. "Being in some of the situations I've been in, that excites me."

Pressure is on

This is Sparano's sixth stint as an offensive line coach since he broke into coaching at his alma mater, New Haven, in 1984.

"I was a Division III center and I wasn't very good," he said. "But I was smart and I made my way around the field pretty good."

In Minnesota, his plate has been filled and packed with the pressure that comes with being handed a team's top priority. Sparano's guidance started long before he yelled at his first purple jersey.

"Part of my issue with [the] offensive line was I could never figure out what we're looking for in an offensive lineman," Zimmer said. "What are the traits we're looking for? Tony was able to come in and speak clearly and show us what we're looking for on tape. I think that's a big help to the scouts."

Zimmer also has made it no secret that Sparano and new tight ends coach Pat Shurmur were hired in part to help offensive coordinator Norv Turner tweak an offense that ranked 29th overall and 31st in passing last season.

"I don't think our scheme is going to change a whole lot, but there are some new ideas right now just because there are two new coaches," Sparano said. "Coaches come with ideas. Norv has been great listening to them."

The players, of course, can't help but hear Sparano's message on the field.

"He certainly lives up to the billing," center John Sullivan said with a smile. "I've got a feeling [training camp] is going to be a big change in terms of how much we get yelled at. Even as an adult, you don't like to get yelled at, so it can definitely ramp things up in terms of intensity and attention to detail."

Sparano also has made sure to remind his 16 students that the head coach publicly questioned the offensive line's mental toughness.

"I've played a lot of football for a lot of different coaches, and offensive line is offensive line," Berger said. "In the run game, move somebody. In the pass game, stop the other guy from getting your quarterback.

"There are little details … that are important. But when the coach challenges your toughness, you take it personally, which obviously was the whole point of it."

Finally, when the pads go on next week and the most trustworthy analysis begins, Sparano will have to work quickly to help Zimmer and Spielman identify and/or confirm as many as four starting jobs and nearly every backup role. Center, right guard and right tackle each have two players with at least 33 NFL starts.

Zimmer was asked if one could assume that left guard Alex Boone and left tackle Matt Kalil are locked in as starters. Boone is this year's prized free-agent signing, while the team anteed up on the inconsistent Kalil's one-year, $11.1 million option.

"I would assume Boone, probably," said Zimmer, no doubt poking Kalil with a branch right off the Parcells motivational tree.

Zimmer obviously will make all final on-field decisions. But he's leaning heavily on Sparano's knowledge. And the eyes behind those famous sunglasses.

"The funny conclusion to that story is when the patches finally came off my eyes, I was on the mound pitching a game," Sparano said. "I got stuck out there and gave up 15 runs in like two innings. I walked 12 batters."

Sparano laughs and jokes, "But I can see fine now."