Frosinone Calcio
Starting in 2015, after the move to Keyworth, Detroit City began a yearly tradition to invite at least one international club for a friendly per year. This excludes Windsor TFC, which is based just miles away in neighboring Windsor and has been played yearly since the club's first season. These invitations are often extended to a club that has a similar mentality to Detroit City, or holds historical significance to the city of Detroit. The 2018 match against Serie A side Frosinone Calcio set a new club attendance record of 7,887. In 2019, after announcing that the club was to play Lobos BUAP of Mexico, Lobos faced financial trouble and was replaced both in the Liga MX and the friendly with FC Juárez.