From the eighth to the nineteenth year Kapellmann went through all youth classes in his home club, the SC 1930 Bardenberg, before 1968 a professional contract at Alemannia Aachen signed. His Bundesliga debut was a successful, because his club won on August 17, 1968 ( 1st Round ) 4-1 goals during the reigning champion, the first FC Nuremberg. His first Bundesliga goal he scored on 19 October 1968 ( 10th Round ) for interim 1:1, in the 2:4 home defeat against Bayern Munich. For Aachen he also played seven DFB Cup games.
From 1970 to 1973 he belonged to the squad of the 1st FC Cologne, for which he was also first used in European Cup competition; a total of 17 times ( 3 goals ). In addition, he played 20 times in the DFB Cup ( 2 goals) and was established in 1973 A-National player. In his time at Cologne, he studied the way business administration.
With FC Bayern München - who had paid the very high for that time transfer fee of 800,000 DM for a change - he was from 1973 to 1979 to celebrate his athletic achievements. 16 DFB Cup games ( 3 goals ), 32 European Cup games ( 1 goal), two World Cup matches and two in the senior team, he played also for Bayern Munich. Also at this time he pursued a course of study, moved to Munich, however, the field of study to medicine. Then his nickname founded pharmacy.
He then moved of their own accord for TSV 1860 München - by its own account also because his former teammate Uli Hoeness, to which there has always been a strained relationship, Manager at Bayern was and he did not want to work with Hoeness as supervisor. Uli Hoeness remarked, Kapellmann was probably left because he knew that he ( Hoeness ) did not want to extend his contract.
At the 1860 Munich he was injured soon hard on his right knee. Despite intensive rehabilitation, he was not back to his old form and ended with his final game on February 14, 1981 ( 21 Matchday) in the 1-1 draw against 1 FC Kaiserslautern his footballing career. Kapellmann graduated 338 Bundesliga matches, scoring 36 hits.
On November 26, 1967 Kapellmann debuted in the national team, and scored the only goal in the 1-3 defeat of the DFB youth team in Flensburg against the selection Denmark. In 1968 he came to this selection is used six times, including in three games during the UEFA youth tournament in France. From 1969 to 1973 he played six times for the U-23 national team, for the first time on September 24 in the 1-2 defeat against Romania in Bucharest, the last time on March 27. Duisburg 's 5-1 victory over the United States For the B team, he came three times to use; 1972, 1974 and 1975 each time. On May 12, 1973, he made his debut in the senior national team, which won 3-0 against Bulgaria in Hamburg. His last game he played on November 20, 1974 in Piraeus in a 2-2 draw against Greece when he came on in the 78th minute for Bernd Cullmann.
- World Champion 1974 ( without insert)
- World Cup winners in 1976 with FC Bayern Munich
- European Cup Winners ' Cup in 1974, 1975, 1976 with FC Bayern Munich
- German champions in 1974 with FC Bayern Munich