6. Matt Duchene trade backfires immediately
After falling in the 2017 Eastern Conference Finals, it was obvious the Senators were missing a key offensive piece to give an extra boost. One month into the 2017-18 season, the Senators completed a three-team trade with the Colorado Avalanche and Nashville Predators to acquire former 2014 Gold Medal Olympian Matt Duchene.
Duchene had grew frustrated in Colorado and wanted a trade out. When Duchene was traded to Ottawa, he appeared to be the missing piece as Ottawa had a 6-3-5 record at the time of the trade.
Instead, the Duchene trade would set the Senators back. The Senators traded fan favorite Kyle Turris to the Predators. While Turris didn't perform well with the Predators, the key draft pick the Avalanche received in the trade was the Senators' 2019 first-round draft pick. Had the Senators not trade away the draft pick, they could've had the chance to select players from Moritz Seider, Dylan Cozens or Trevor Zegras.
Duchene would be traded by the Senators to the Columbus Blue Jackets before the 2019 trade deadline, and Duchene would help the Blue Jackets win their first playoff series in franchise history in 2019. After Ottawa, Duchene would record a career-high 43 goals and 86 points in the 2021-22 season with the Predators. Today, Duchene is a key player on the Stars roster.
The Avalanche would win the 2022 Stanley Cup after the trade, and the Senators have failed to make the playoffs since the trade.