Hoydonckx was a left back at Berchem and Tilleur who became the best left back in the country and a fixture in the national team. He remained a national team player, even when he joined third division club Excelsior Hasselt. He took part in the 1928 Olympic Games and the World Cup in 1930. He played his last match for the national team on 26 November 1933 against Denmark to become the last player from the 19th century to appear for the Red Devils.