Chiasson, an impending restricted free agent, has been on the trade market for weeks. The Flames promptly signed the forward to a one-year contract worth $800,000 — a decrease from the $1.2 million he earned in 2015-16.
A native of Montreal, Chiasson played 77 regular season games for Ottawa in 2015-16, picking up seven goals, eight assists and 45 penalty minutes.
Since being selected by the Dallas Stars in the second round of the 2009 NHL Draft, Chiasson has scored 38 goals and added 44 assists for 82 points in 239 career NHL games.
Ottawa acquired Chiasson from Dallas as part of 2014’s multi-player deal that featured Jason Spezza.
The 22-year-old Sieloff made his NHL debut last season, playing one game with Calgary. In his lone game, he scored the game-winning goal in the Flames’ 2-1 victory over the Minnesota Wild on April 9. In 52 games with the American Hockey League’s Stockton Heat, he scored two goals, nine assists and recorded 54 penalty minutes.
The 6-foot-1, 205-pound native of Superior, Mich., was Calgary’s second-round selection (42nd overall) in the 2012 NHL Draft. Sieloff has represented the United States internationally on three occasions, winning gold at the 2013 IIHF World Junior Championship in Russia.