The former Germany fullback is now coaching FC Pinzgau Saalfelden of Austria's third tier.
He told the Daily Mail: "I didn't play enough and still don't know why. I scored a penalty in the shootout to win the League Cup but then didn't play in the FA or UEFA Cup finals.
"Gerard Houllier had a problem that he never bothered to explain. It made me think, 'If I'm a coach, I'll always tell my players the truth'."