 Theriault was awarded the 1986–87 Matt Leyden Trophy as the OHL Coach of the Year.At the professional level, Theriault was an assistant coach with the Buffalo Sabres during the 1996–97 NHL season when Ted Nolan won the Jack Adams Award as the NHL's Coach of the Year.He has also served as head coach for the Flint Spirits of the International Hockey League and the HC Asiago and HC Varese of the Italian Serie A.

Theriault suffers from the debilitating effects of post-concussion syndrome resulting from when he was an NCAA player with the Lake Superior State Lakers men's ice hockey team from 1968 to 1971.