Mair sustained concussion Jan. 12 during a collision with Phoenix forward Tyson Nash and missed 31 games before returning to play earlier this month. He played two games before having more symptoms.
"He just doesn't feel right," coach Lindy Ruff said Monday. "Until we get him through that, he won't be skating."
Mair finishes the year with two goals and seven points in 40
Meanwhile, Sabres forward Jochen Hecht continues to make progress after spraining a ligament in his left knee April 3 against Toronto. Hecht joined 12 players in Monday's optional practice.
He remains day-to-day, and will miss Buffalo's season-finale Tuesday night in Carolina.