Thomaris joined the Jackals' coaching staff during the 2013-14 season as an assistant coach. He primarily worked with the defense underneath former head coach Dwight Mullins. Prior to joining the Jackals, Thomaris served as a head coach for five seasons (2002-2007) at SUNY-Potsdam, where he began his coaching career as an assistant coach in 1978. The Potsdam, NY native compiled a 47-75-12 record with SUNY-Potsdam.
Before taking over at SUNY-Potsdam, Thomaris spent 14 years behind the bench at Elmira College. He amassed a 270-122-14 record, which included five ECAC West championships and seven appearances in the NCAA tournament. He was named the NCAA Division III coach of the year by the American Hockey Coaches Association in 1988 and 1991.
Thomaris also served as the head coach at his alma mater, the Northwood School, in Lake Placid, N.Y., for two seasons before becoming an assistant coach at Clarkson University, where he played from 1974-1977. Thomaris recorded 44 points (20 goals, 24 assists) in 86 career games at Clarkson.