Passage: Günter Theodor Netzer (born 14 September 1944 in Mönchengladbach) is a former German football player and team general manager currently working in the media business. He achieved great success in Germany with Borussia Mönchengladbach in the early 1970s, and, after moving to Spain in 1973, with Real Madrid. He played as an attacking midfielder, and is considered one of the greatest passers in the game's history. He was voted Footballer of the Year in Germany twice, in 1972 and 1973. He was the general manager for Hamburger SV during much of the team's golden period from the late 1970s through the early 1980s, when the club won three league titles and the 1983 European Cup.

Question: What position did Gunter Theodor Netzer play when he still played football?
attacking midfielder