[1] Helmer spent most of his club career with Borussia Dortmund and Bayern Munich – appearing in nearly 400 Bundesliga games in 15 seasons – and won the European Championship in 1996.

Born in Herford, West Germany, Helmer began his professional career with Arminia Bielefeld, playing four games late in 1984–85, in a season that ended in relegation.

The resulting furore became so heated that the Germany national side coach Berti Vogts threatened to drop Helmer from the UEFA Euro 92 squad because of the distraction the affair was causing.

Although he had appeared in the UEFA Champions League for Hertha, upon his return to Sunderland, Reid judged that "his legs had gone", and the club bought-out his contract,[5] with the player retiring immediately afterwards.

Helmer also appeared in two FIFA World Cups, bowing out of international football in the second round clash of the 1998 edition against Mexico, when he was replaced before half-time by Christian Ziege.