Pysyk, 28, set career highs by posting nine goals and 18 points (9-9=18) in 58 regular-season games played for Florida in 2019-20. Finishing with a +4 plus/minus rating, he was also used at right wing at times throughout the season. In four postseason contests, he registered eight shots on net and did not record a point.
Appearing in 417 regular-season games over eight seasons with Buffalo and Florida, he has recorded 88 career regular-season points (22-66=88). He also earned a bronze medal, along with Jamie Oleksiak, for Canada at the 2010 World Jr. Championship.
"Mark is a solid, puck-moving defenseman and gives us another right-handed shot on the backend," said Nill. "We feel that his skillset lends itself to how we ask our defensemen to activate and he will be a good fit."
The 6-foot-1, 196-pound native of Sherwood Park, Alberta was originally selected by Buffalo in the first round (23rd overall) of the 2010 NHL Draft.