Kesselring, a 26-year-old defenseman, had two assists in 34 regular-season games for the Sabres this season and no points in one Stanley Cup Playoff game.
He is in the last of a two-year, $2.8 million contract ($1.4 million average annual value) he signed with the Utah Mammoth on June 28, 2024, and can become a restricted free agent on July 1.
"Michael has a big frame (6-foot-5, 215 pounds) with solid two-way ability," Sharks general manager Mike Grier said. "He is a responsible player in the defensive zone with a well-rounded offensive game, and will be a good upgrade for us patrolling the blue line. We're happy to have him a part of the organization."
Kesselring was acquired by Buffalo from Utah, along with forward Josh Doan, for forward JJ Peterka on June 26, 2025.
Selected by the Edmonton Oilers in the sixth round (No. 164) of the 2018 NHL Draft, Kesselring has 55 points (12 goals, 43 assists) in 190 regular-season games for the Arizona Coyotes, Mammoth and Sabres.
The Sharks (39-35-8) finished fifth in the Pacific Division, four points out of a playoff spot in the Western Conference. They had 86 points, a 32-point improvement from last season, when they finished with the worst record in the NHL.
San Jose has eight selections in the 2026 draft, including the No. 2 pick.
The Sabres (50-23-9) won the Atlantic Division this season and qualified for the playoffs for the first time since 2011; they lost to the Montreal Canadiens in seven games in the second round. Buffalo has four picks in the draft.
The No. 20 selection initially belonged to Edmonton.
