Muller was also a member of the California track and field team. The Bears won the ICAAAA championships in 1921, ’22, and ’23, and also won the second NCAA championships. Muller placed second in the Broad Jump, third in the High Jump, and fourth in the Discus Throw.
After graduating from Cal, Muller wanted to become an orthopedic surgeon. He was accepted into the University of California's Medical School, but was in need of money. To help supplement his income while in medical school, Andy Smith hired Muller to coach the ends on the Cal varsity. While in school Muller coached from 1923–1925, until Smith died from pneumonia in 1926. After he became a physician, Brick played in the first East-West Shrine Game. During the game, he caught a 27 yard pass for a touchdown. Ed R. Hughes of the San Francisco Chronicle wrote in his column: “Remember Muller has been out of college for three years, but right now he is by far the greatest end in the West, and probably one of the best that ever played!!” This led to Muller being signed by the Los Angeles Buccaneers. He soon became the player and head coach of the team. He led the Buccaneers to a 6-3-1 record in 1926. The team later folded in 1927.
The Brick Muller Award, which was first given in 1949, honors Muller and is awarded to the most valuable lineman on the Cal team. Players who won the award three times include Ralph DeLoach, E (defense; 1977-79), Harvey Salem, T (offense; 1980-82), Majett Whiteside, NG (defense; 1985-87); Andre Carter, DE (defense; 1998-2000), and Mitchell Schwartz, left tackle (offense; 2009–11).