Mulder was born in
Brussels, Belgium. The son of former
Ajax Amsterdam and
R.S.C. Anderlecht player
Jan Mulder, he played youth football for
SDO Bussum and Ajax. After two years in amateur football, he made his professional debuts at 21, with
FC Twente. In
his second season, he scored a career-best 18 goals, as the club finished sixth in the
Eredivisie. In 1993, Mulder moved to the German
Bundesliga with
FC Schalke 04, where he would play for nearly one decade. He made his league debut on 7 August, in a 0–3 loss at
SG Wattenscheid 09. His first three years at the
Gelsenkirchen side were successful individually – 22 goals combined – and the
1996–97 season brought with it the
UEFA Cup conquest, with the player netting three times in the campaign, including once in the quarter-finals against
Valencia CF. Additionally, Mulder also won two consecutive
German Cups, in
2001 and
2002. Only managing to appear 33 times (with just one goal) in his last three seasons combined, he retired at the end of
2001–02, aged 33. In
2007–08, Mulder had his first coaching experience: he started the season as an offensive trainer in Twente, then rejoined another former side, Schalke 04, in April 2008, working with former teammate
Michael Büskens as replacements for dismissed
Mirko Slomka, a situation which occurred again in 2009, after the sacking of
Fred Rutten, being joined then by another former club player,
Oliver Reck. ==International career==