Alfred Au began his career in 1917 at the site of the later empire coach Otto Mink and moved three years later to its position as the left runner, as mink from 1920 took over the training of VfR Mannheim. The athletic and lanky athletes recommended by appeals to the city team Mannheim and the Odenwald district for the first time on April 10, 1921 for the selection of Southern Germany the Federal Cup match against Northern Germany. With the VfR Mannheim, he took part in the round 1921/22 on the final round of the South German championship. With coach Joe Bache team of Alfred Au won the first round in 1924/25, the championship in the Rhine district before Phoenix Ludwigshafen and the SV Waldhof. The title caught in southern Germany in the aftermath the lawn athletes before 1 FC Nuremberg FSV Frankfurt, Stuttgart Kickers and the SV Wiesbaden. In the final round of the German soccer championship 1925, the favorite from Mannheim subsequently lost on 3 May 1925 at Weidenpescher Park in Cologne before 12,000 spectators against TuRU Dusseldorf with 1:4 goals. Au was at left- runner, Karl Hoger as a right winger and Sepp Herberger as a center forward while unsuccessful in use for the VfR Mannheim.
With the federation selection of Southern Alfred Au was three times in the semifinals to the Federal Cup. First 1921/22, on 13 November 1921 in Fürth against Brandenburg where he was the runner series with calf and Carl Hans Riegel from 1 FC Nuremberg 3-0 success. The second semi-final, he played a year later, on November 12, 1922 in Chemnitz in a 4-1 victory against the selection of Balts. But in the two winning finals of 1922 and 1923 he did not play for southern Germany. After the third semi-final success on November 9, 1924 in Mannheim against Brandenburg he was also on February 22, 1925 in Hamburg in the final against North Germany. The South lost the final with 1:2 goals. Already on September 18, 1921 came the Mannheim at the international game in Helsinki against Finland to a use in the German national soccer team. He formed together with Karl Tewes and Walter Krause runners set the DFB team. The Hans used as a center forward calf and the inside right Sepp Herberger made the German goals in the 3-3 draw. Further vocations to the national team did not get Alfred Au.
Alfred Au worked in the Electoral Palatinate region for decades as an architect. Before the Game Round 1948/49, he was the head of a square Commission, the ruined place at the breweries could ask for VfR Mannheim again available in a six-month construction period.