"This isn't how I envisioned this or planned this. but I'm going to retire".
Luck sat out the 2017 season with a shoulder injury, and returned in 2018 but got out to a rocky start before a stellar year in which he won the Comeback Player of the Year.
Colts fans picked up the news of his retirement during the game, and even booed Luck as he walked off the field following their 27-17 loss, too.
Luck will turn 30 next month.
"I had a thought that it might be my last time throwing at Lucas Oil as a current member of the Colts team", Luck said.
Bernie Sanders Rallies Supporters In Downtown Sacramento
The plan does not include a carbon tax, which Sanders has supported in the past. He calls for eliminating all emissions from the transportation sector by 2030.
Hong Kong protesters throng streets in heat and heavy rain
Another weekend of protests is underway in Hong Kong, with teachers rallying to support students and other protesters. Police had not approved a march on Sunday.
D23: First Look at Eternals Costumes, Plus Kit Harington & More Join Cast!
He is now nominated for the Outstanding Actor in a Drama Series Emmy for his work as Jon Snow in the show's final season. Angelina Jolie and Richard Madden are headlining the Eternals as Thena and Ikaris, respectively.
"This is not an easy decision", he told reporters.
Luck, according to the report, is "mentally worn down" and is "now checking out". This offseason has been marred by a "high-ankle" injury that kept him out of the majority of training camp and organized team activities. But a slew of injuries forced Luck to miss extended periods of time and those ailments clearly took a toll on the quarterback's psyche, and apparently he's had enough of the National Football League lifestyle.
After that victory, Luck missed the next two weeks as he recovered from the injury.
Jacoby Brissett, who also didn't play Saturday, would take over as the starter. Back at full strength, Luck led Indianapolis to the divisional round of the playoffs after completing 67.3 percent of his passes for 4,593 yards and 39 touchdowns during the regular season.
But he returned last season, played all 16 games and made the Pro Bowl. While he played almost all of the 2016 season, Luck's shoulder still impacted him - eventually forcing him to have surgery on it that offseason, which sidelined him for all of 2017. It was during the 2017 season while out that Luck questioned whether he would be able to continue his career.