Following his Olympic victory, Müller took a year off from rowing. In 1998, he won two World Cup race besting future rival Rob Waddell. But at the World Rowing Championships, Waddell had the best race of his life pushing Müller back to second. In the pre-season to the 1998 rowing calendar, Waddell set a world record on the indoor rowing machine. In 1999, Waddell went on to sweep the World Cup races and the World Championships, Müller getting second each time.