According to Grant Wahl's wife, Dr. Celine Gounder, the American journalist passed away as a result of an undiscovered aortic aneurysm rupturing.

While covering last Friday's World Cup quarterfinal between Argentina and the Netherlands at Lusail Stadium, the 49-year-old passed out in his chair.

Wahl was attended to by medical personnel inside the area and brought to a hospital, but when his passing was eventually confirmed, a flood of condolences quickly followed.

On Monday, after being flown back to New York City, an autopsy determined the reason of his death, with wife Gounder excluding any possibility of foul play.

"Grant died from the rupture of a slowly growing, undetected ascending aortic aneurysm with hemopericardium," Gounder posted on her husband's blog.

"The chest pressure he experienced shortly before his death may have represented the initial symptoms. No amount of CPR or shocks would have saved him.

"His death was unrelated to COVID. His death was unrelated to vaccination status. There was nothing nefarious about his death."

On behalf of myself and our family, I want to express our deepest gratitude for the outpouring of support, love, and sympathy from around the world. Here is a message from our family and the latest update surrounding our beloved Grant:

— Céline Gounder, MD, ScM, FIDSA 🇺🇦 (@celinegounder) December 14, 2022

Wahl, who was best known for his long career with Sports Illustrated, attended a medical clinic at Qatar 2022's Main Media Centre four days prior to his death after feeling unwell and was diagnosed with bronchitis.

The much-respected reporter was at the centre of controversy earlier in the World Cup when he sported a rainbow t-shirt in support of LGBT rights as he attempted to attend a match.

He was initially prevented from entering Ahmad bin Ali Stadium for the United States' group game against Wales, although he was later allowed inside.

Wahl's brother suggested he had been "killed" in the immediate aftermath of his death, but he later said he "regretted" those comments and no longer believed that to be true ahead of Wednesday's announcement.

Paying her own respects to her husband, Gounder said: "We will forever cherish the gift of his life; to share his company was our greatest love and source of joy.

"Grant was an incredibly empathetic, dedicated and loving husband, brother, uncle and son, who was our greatest team-mate and fan.

"While the world knew Grant as a great journalist, we knew him as a man who approached the world with openness and love."