Sun Yue
Müller won gold medals at the 2008 and the 2009 World Mixed Doubles Curling Championships with his partner Irene Schori. However, they finished seventh at the 2010 World Mixed Doubles Curling Championship after being beaten by the Chinese team of Sun Yue and Zhang Zhipeng in an extra end in the quarterfinals. In an interview post-match, Schori stated that she and Müller would consider not attending next year to give a chance to other Swiss teams to compete.