Tributes have been pouring in following the shocking death of Indianapolis Colts owner Jim Irsay ... with plenty of former players, coaches and loved ones taking time to remember the 65-year-old -- including the team's Super Bowl-winning quarterback, Peyton Manning.
The 49-year-old took to his Instagram to speak on Irsay's passing ... calling him an "incredibly generous and passionate owner, and I will always be indebted to him for giving me my start in the NFL.