In 1952 and 1953 he played two matches with the Red Devils, the Belgium national team.
Thys was appointed Belgium football manager in 1976 and remained in the job until 1989, managing the team for 101 games.
He started his career in the 1940s and 50s as a football player with Beerschot, Daring Molenbeek and Standard. In 1952 and 1953 he played two matches with the Red Devils, the Belgium national team.
He combined the activities of player and trainer for Cercle Brugge from 1954 until 1958. In 1959 he performed the same functions for Racing Lokeren.
Thys was a Belgian football manager, mostly known for being the most successful manager in the history of the Belgium national football team as he managed to lead the national side to their only UEFA European Championship final in 1980 and a fourth-place finish at the 1986 FIFA World Cup.