Tim Gelzinis is an assistant coach for the University of Massachusetts Amherst baseball program in Amherst, Massachusetts. He joined the UMass staff in August 2024 after spending two seasons as an assistant coach at Roger Williams.
At UMass, Gelzinis was on staff during a season in which Jack Beverly earned Atlantic 10 All-Academic Team honors in 2025, while Beverly and Marc Willi were also recognized on the College Sports Communicators Academic All-District Team. Before arriving at Massachusetts, he worked with hitters, outfielders, and baserunners at Roger Williams. His time there included eight All-Conference selections, All-Region honors for Jack Morin in 2024, a season in which the program was nationally ranked for several weeks, and a win over top-ranked Division III Endicott for the first time in school history. He also contributed to a 2023 season that set the program record for stolen bases with 120.
