He began playing professional ice hockey in 1992 and played his entire career in Germany, playing the Eishockey-Bundesliga for EC Hedos München and the Deutsche Eishockey Liga for Maddogs München and Ratinger Löwen.

Mueller was drawn to poker after one of many long road trips during his hockey career.

After retiring from hockey, he decided to take the game more seriously and began playing in tournaments.

[5] Mueller won his first World Series of Poker title in 2009 in the $10,000 limit Texas hold'em championship.

[6] Mueller won his second World Series of Poker bracelet and $194,909 only 11 days after his first in a $1,500 Limit Hold'em Shootout event.