Tony Sparano, a two-time NFL head coach who had been the Vikings offensive line coach since 2016, died Sunday morning at the age of 56, the team said.

"Our hearts go out to Jeanette and the entire Sparano family as we all mourn the loss of Tony," Vikings owners Mark and Zygi Wilf said in a statement. "Tony was a passionate and driven individual who cared deeply about his family, and especially enjoyed spending time with his grandchildren.

"Tony's presence within the Vikings organization will be deeply missed. We are only thinking of Tony's family during this incredibly difficult time. We ask that the entire NFL and Vikings family keep the Sparanos in their thoughts."

Emergency personnel were notified shortly after 8 a.m. Sunday of Sparano's need for medical attention.

Dispatch audio revealed that a female was performing cardiopulmonary resuscitation on Sparano at the home in the Bearpath gated community in Eden Prairie.

ESPN reported that Sparano recently had complained of chest pains and went to the hospital Thursday, before being released Friday following a round of tests. According to ESPN, Sparano's wife, Jeanette, found him unconscious in the couple's kitchen when both were about to leave for church Sunday morning.

The news stunned the Vikings organization two days before rookies were scheduled to report to training camp at the team's new practice facility in Eagan. Sparano, known around the league for his no-nonsense approach and a gruff demeanor that belied a gregarious personality, was set to be back in the building Monday as coaches returned to work.

"I am at a loss for words with Tony's sudden passing," General Manager Rick Spielman said in a statement. "Tony loved the game of football and his players. More importantly, he was a strong man of faith who treasured his family. My heart is with the Sparanos today. As an organization we will support them in whatever ways we can."

Said Vikings coach Mike Zimmer in a statement: "I love Tony Sparano. He was a great teacher, a grinder of a worker and had a toughness and fighting spirit that showed in our linemen. He was a great husband, father and grandfather and a great friend to me. This is just sinking in for us but Tony will be sorely missed by all."

Former Vikings lineman Joe Berger, who played for Sparano in Dallas and Miami before winning the team's starting center job in Sparano's first year in Minnesota, said the coach teased him in 2016, saying, "You're like a bad penny — I just can't get rid of you."

Sparano became one of Berger's biggest advocates throughout the Michigan Tech product's 13-year career. Berger, who retired this spring, is on vacation in Colorado this week and plans to stop by Vikings training camp this weekend while driving a RV back to his home in western Michigan. While there, he said, he had planned to shake Sparano's hand and thank him for all his help through the course of his career.

"I think he comes off as dry and a little grumpy, maybe, but when you get to know the guy, he wants what's best for you," Berger said. "He was going to tell you what you needed to hear to be a better player and a better person. He was a caring guy. He loved his family. When he would be grumpy at training camp, I would ask him how his grandkids are doing, and his face would immediately change.

"When I first got to Dallas, I was a second-year player. He comes across as so grumpy, and yelling at you, like you can't do things right. The more time you spend with him, you realize he's just talking to you like that because he sees something in you that you don't. He had a real knack for bringing out the best in you as a player."

Sparano was head coach of the Miami Dolphins from 2008 to '11, winning an AFC East title in his first year. He also served as interim coach of the Oakland Raiders for the final 12 games of the 2014 season.

With the Vikings, he replaced Jeff Davidson as offensive line coach two years ago, rejoining Zimmer nine years after the two had last worked together with the Cowboys. He came to Minnesota after a year as San Francisco 49ers tight ends coach, and worked with new Vikings offensive coordinator John DeFilippo while both were in Oakland in 2014.

Despite all of the ups, downs and never-ending relocations throughout his career, Sparano, from West Haven, Conn., never lost sight of his humble beginnings.

As a 16-year-old, he nearly lost his vision in a fast-food restaurant work accident that sent hot oil exploding into his face.

That's why he was rarely seen without his signature sunglasses.

"You can see there's still a scar on my face," Sparano told the Star Tribune shortly after taking the Vikings job in 2016. "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."

He will be remembered for those glasses, but for much more. A football coach who followed his passion all over the NFL, an offensive line specialist who proved he could step into big moments as he did in Miami, and in Minnesota as someone who could help turn around an offense.

Sparano is survived by wife Jeanette, sons Tony and Andrew, daughter Ryan Leigh and four grandchildren. The Vikings said they would "provide further updates when appropriate."