Senators have a long history of trades of players that haven’t worked out:

Mike Fisher
Traded from Ottawa Senators to Nashville Predators for round 1 pick in the 2011 draft (Stefan Noesen) and round 3 pick in the 2012 draft (Jarrod Maidens)

Jason Spezza
Traded from Ottawa Senators with Ludwig Karlsson to Dallas Stars for Nick Paul, Alexander Guptill, Alex Chiasson and round 2 pick in the 2015 draft (Mackenzie Blackwood)

Chris Kelly
Traded from Ottawa Senators to Boston Bruins for round 2 pick in the 2011 draft (Shane Prince)

Antoine Vermette
Traded from Ottawa Senators to Columbus Blue Jackets for Pascal Leclaire and round 2 pick in the 2009 draft (Robin Lehner)

Radek Bonk
2004-Jun-26 Traded from Ottawa Senators to Los Angeles Kings for round 3 pick in the 2004 draft (Shawn Weller)

Martin Havlat
Traded from Ottawa Senators with Bryan Smolinski to Chicago Blackhawks for Josh Hennessy, Tom Preissing, Michal Barinka and round 2 pick in the 2008 draft

Marion Hossa
2005-Aug-23 Traded from Ottawa Senators with Greg De Vries to Atlanta Thrashers for Dany Heatley

Dany Heatley
2009-Sep-12 Traded from Ottawa Senators with round 5 pick in the 2010 draft (Isaac Macleod) to San Jose Sharks for Jonathan Cheechoo, Milan Michalek and round 2 pick in the 2010 draft (Kent Simpson)

Erik Karlsson
2018-Sep-13 Traded from Ottawa Senators with Francis Perron to San Jose Sharks for Dylan DeMelo, Chris Tierney, Rudolfs Balcers, Josh Norris, round 2 pick in the 2019 draft, conditional round 1 pick in the 2020 draft, conditional round 2 pick in the 2021 draft and conditional round 1 pick in the 2022 draft

Kyle Turris
2017-Nov-05 Traded from Ottawa Senators with Shane Bowers, Andrew Hammond, conditional round 1 pick in the 2018 draft and round 3 pick in the 2018 draft to Colorado Avalanche for Matt Duchene

Mike Hoffman
2018-Jun-19 Traded from Ottawa Senators with Cody Donaghey and round 5 pick in the 2020 draft to San Jose Sharks for Mikkel Boedker, Julius Bergman and round 6 pick in the 2020 draft

Mika Zibanajed
from Ottawa Senators with round 2 pick in the 2018 draft to New York Rangers for Derick Brassard and round 7 pick in the 2018 draft

Milan Michalek
2016-Feb-09 Traded from Ottawa Senators with Jared Cowen, Colin Greening, Tobias Lindberg and round 2 pick in the 2017 draft (Eemeli Rasanen) to Toronto Maple Leafs for Matt Frattin, Ryan Rupert, Dion Phaneuf, Casey Bailey and Cody Donaghey

Dion Phaenuf
Traded from Ottawa Senators with Nate Thompson to Los Angeles Kings for Nick Shore and Marian Gaborik

Not many have worked out, by the looks of things the best one will be EK65’s