Ryan released the following statement Friday afternoon, per TSN's Ian Mendes.
"While the news this morning came as a bit of a shock, I understand the decision. The Sens are an upcoming young team with so many bright years ahead of them. I'm excited to follow along as a fan of all the young players with the rest of you," Ryan said.
"Ottawa will have a special place in our families heart forever. See you around the ice."
Ryan has two seasons remaining on his current deal, which includes a $7.25-million cap hit per campaign. The 33-year-old winger is owed $11 million in salary over the next two seasons.
Ryan will count for $3.83 million per season on Ottawa's books for the next two years following the buyout, and $1.83 million per season for the two years after, according to CapFriendly.
With Ryan in the mix, the Senators needed to spend $18 million to get to the salary-cap floor, per The Athletic's Hailey Salvian.
Ottawa currently has 10 players under contract for next season.
The Senators acquired Ryan from the Anaheim Ducks via trade prior to the 2013-14 season. He registered 266 points in 455 games with Ottawa.
Ryan won this season's Masterton Trophy as the player who best exemplifies the qualities of perseverance, sportsmanship, and dedication to hockey. He left the Senators to enter the NHL/NHLPA player assistance program in November and later revealed his struggle with alcohol abuse. Ryan rejoined the club in February and registered a hat trick in his first home game.