Rasmus Ristolainen
Rasmus Ristolainen is slightly older (30 years old) than Dobson or Byram but would still give the Leafs what they're looking for.
He has size (6'4, 208 Lbs), is a right-shooting defenseman, and can play top pairing minutes. Like the other two, Ristolainen is a former first-round pick. He was selected 8th overall by the Buffalo Sabres in the 2013 NHL draft, though he's never come close to living up to that selection.
Ristolainen has four goals and 15 assists for 19 points in 58 games this season for the Philadelphia Flyers. He is averaging 20:30 minutes of ice time this season and could handle playing in the Leafs top pairing. The Finnish-born defenseman also has 90 hits and 88 blocked shots this season.
Unlike Dobson or Byram, Ristolainen is signed beyond this season. There is an understanding that Leafs GM Brad Treliving would prefer to add players who would be just a rental player. Ristolainen is under contract until the end of the 2026-27 season, though his cap hit his high for what he does.
Acquiring Ristolainen would likely not cost as much as acquiring Dobson or Byram, but a top prospect or the 2026 first-round pick would still be involved. Dobson and Byram are star-level players who instantly become the Leafs best defenseman, while Ristolainen would only be their 5th best defenseman and isn't an ideal upgrade for this reason.
Ristolainen has a salary cap hit of $5.1 million for three more seasons until he becomes an unrestricted free agent (UFA) in 2027. The Leafs could either increase their offer and ask the Flyers to retain some salary, or the Leafs could find a third team to help with the salary and offer that team a prospect as well.