Grant Wahl's wife says "there was nothing nefarious" about the soccer journalist's death ... explaining on Wednesday that the 49-year-old died from a ruptured aortic aneurysm.
Dr. Celine Gounder -- an infectious disease expert and Wahl's wife since 2001 -- told CBS News in a sitdown interview that Wahl's dire condition "had likely been brewing for years."
"And for whatever reason," she said, "it happened at this point in time."
Wahl suffered a medical episode on Friday night -- while in Qatar covering the Argentina vs.