Doan, 40, has played only for the Coyotes, dating back to before the franchise moved from Winnipeg. He was the seventh overall pick by the Jets in 1995.
"I'm so grateful and thankful to the Winnipeg Jets for drafting me and giving me a chance to play my rookie season and when the team moved to the Valley in 1996, all I wanted to know was if the Coyotes would keep giving me a chance to play," Doan said in a first-person letter published in the Arizona Republic.
"I could not fathom at the time that I would end up playing in Arizona for the next 21 years, raise a family and call this place home. But that's exactly what happened. And that's why this has been one of the hardest decisions I've ever had to make."
Doan, who served as the team's captain from 2003 to 2017, was not re-signed by the Coyotes after last season, as the team said it was time to move on and focus on younger players.
He is the team's career leader in just about every significant category, including games played (1,540), shots (3,945), goals (402), assists (570), points (972), power-play goals (128) and game-winning goals (69). His 1,540 games played is tied with John Bucyk for 14th on the NHL's all-time list.
"We would like to thank Shane for everything that he's done for our franchise over the past 21 years," the Coyotes said in a statement. "Shane had an incredible career on the ice and we are very proud of everything that he accomplished in a Coyotes uniform.
"He will be remembered as one of the greatest captains in NHL history. Off the ice, Shane was a great ambassador for growing the game of hockey in Arizona and his contributions to the community are immeasurable. Shane will be a Coyote for life. Thank you Captain!"
Doan was a two-time NHL All-Star selection and also was awarded the King Clancy Memorial Trophy, given to the NHL player who best exemplifies leadership qualities on and off the ice, in 2010. He won five medals, including two golds, representing Canada at the world championships.
"I've been blessed and I'm so grateful for the fans and their support," Doan wrote. "They stuck by me throughout my career and the ups and downs of the Coyotes. There are a lot of players with more skill than me and a lot more ability than me that didn't ever get the type of appreciation that I got and the type of respect that the fans gave me, and I'm so grateful for that. I can't express how much I appreciate it. Thank you for watching me grow up, and I enjoyed watching a lot of you grow up, too."
Doan contemplated retirement after the 2014-15 season and ended up having a renaissance after he decided to play at least one more year, as he led the Coyotes with 28 goals while adding 19 assists.
His 21st season was not as productive. Doan had a decreased role -- at least on the ice -- and had a few injuries that slowed him, causing his numbers to drop to six goals and 21 assists.
"Even though my perspective will be different, my love for the NHL won't change and I'll continue to share that passion with the hockey fans in Arizona," Doan wrote. "Thank you for loving the game with me. Thank you for the unwavering support. Thank you for fighting to keep the team here. Thank you for allowing this to be my home.
"And thank you for coming to spend a night with me playing hockey. It's been incredible."