On the Illinois State Redbirds men's basketball team, Muller played as a forward from 1994 to 1998 under head coach Kevin Stallings.
[4] Muller finished his career with 1,445 points and made 128 consecutive starts, which remains a school record.
He was a two-time Missouri Valley Conference Defensive Player of the Year (1996 & 1997) and earned the MVC Tournament MOP in his senior season (1998).
[2] After college, Muller played basketball internationally for two seasons: in Argentina (1999) for Team La Rioja Andino,[3][5] and Belgium (2000) for Siemens Ghent.
[9] Despite the extension, the team was unable to sustain their previous success under Muller, as they suffered consecutive losing seasons in 2019–20 and 2020–21 for the first time since 2005–06 and 2006–07.
Following his departure, associate head coach Brian Jones was named as the interim HC for the rest of the season.
[13] Beginning with the 2023–24 season, he commenced working as a basketball analyst for the Missouri Valley Conference Television Network.