Yamamoto signed a two-year, $3.5 million contract with the Mammoth on Monday.
Yamamoto spent the past two seasons with the Mammoth, most recently recording 13 goals, 10 assists, 47 hits, 20 blocked shots and 14 PIM while averaging 11:48 of ice time across 59 regular-season appearances during the 2025-26 campaign. He was slated to become an unrestricted free agent Wednesday but instead reached an agreement that keeps him under contract with Utah for two more seasons.