Career
He played for Bayern Munich for seven years, winning four German titles and three cups. He retired due to an injury in 1993. He made two more substitute appearances in the 1980-1981 season, replacing Dieter Hoeneß and scoring both times, as Bayern ended the season as German champions.
The following season he made seventeen appearances without getting on the scoresheet, the last of which was the European Cup Final – he started the match, which Bayern lost 1–0 against Aston Villa, being replaced by Günter Güttler after 51 minutes.
Bayern had more luck in the DFB-Pokal, beating 1. Football Club Nuremberg in the final, which Mathy didn"t play in.
1984-1985 was Mathy"s prolific season with Bayern – he scored seven goals on the way to another league title, and another cup final, a defeat to Bayer Uerdingen which Mathy missed. Mathy left Bayern in at the end of the 1986-1987 season having made exactly 100 Bundesliga appearances for the club, signing for Bayer Uerdingen.
In 1990 he moved to Switzerland to sign for Football Club Wettingen, where he spent two years, before returning to Germany to sign for Hannover 96.
After injuries restricted him to eleven appearances in his first season with Hannover, he retired from football in 1993.