Matt Ryan never expected to leave the Atlanta Falcons and says his trade to the Indianapolis Colts is "bittersweet".

The Falcons confirmed Ryan's departure to the Colts on Monday, with the 36-year-old traded for a third-round pick in the 2022 NFL Draft.

Ryan spent 14 seasons with Atlanta after arriving in 2008, with no player in the NFL throwing for more passing yards than the quarterback's 59,735 over that period.

He completed 67 per cent of his passes in 2021, his highest completion rate since 2018, for 3,968 yards and 20 touchdowns.

Prior to 2021, Ryan threw for 4,000 yards in 10 consecutive seasons, the high point coming in 2016 when he led the Falcons to the Super Bowl.

But with his time at Mercedes-Benz Stadium now over, the 2016 MVP is excited to begin a new journey with the Colts, who parted with Carson Wentz after just one season.

As part of a full page advert in the Atlanta Journal-Constitution published on Wednesday, Ryan said: "Thank you, Atlanta.

"From the moment I landed here, late at night just hours after having been drafted, I felt at home. 

"The team welcomed me, balancing the typical indoctrinations of a rookie with the generous acceptance of wise and experienced veterans. 

"The city supported me, bringing enthusiasm to games but also to the more casual interactions we had day-to-day, I knew how lucky I was.

"When my first NFL pass ended with a touchdown, I admit that I felt like this was all meant to be. 

"I was immediately determined to do as right by Atlanta as Atlanta was doing by me. I carried that determination with me through every season that followed.

"Sports are sports, and there is a reason why we play the game every week. Winners are not preordained, and every drive does not end in a touchdown. 

"Success become all the sweeter, not only because I knew it was not guaranteed, but because I was enjoying it with teammates and fans who worked hard to earn it.

"There were of course disappointments, large and small. That did not shake my faith in this team, or in my determination to deliver. This disappointments became motivations."

Across his 14 years in Atlanta, Ryan was a four-time pro bowler, won the MVP award and set multiple franchise records, including the most career touchdowns.

"I have long thought and often said I would retire as a Falcon. But the changes and growth continue," he added.

"As excited as I am about the this next step in my career, this is a bittersweet moment. I have spent more than a decade playing for you, the fans of Atlanta. 

"You have made all of this worth it, and all of this means something more than what could ever be reflected in a statistic. 

"I appreciate each and every one of you, and I thank you, so sincerely, for the life you have given me all of these seasons.

"I am also very grateful to the coaches and teammates I have played with over the years. 

"There are too many to list here, but I hope each of you know how much you have shaped me as a player and as a person. I look forward to crossing paths, on the field and off.

"It seems impossible to sum up 14 years, and to adequately express my feelings about them. 

"As much as I have learned about change, though, I know this: Nothing can change what this time has meant to me. So, again. Thank you, Atlanta."