Mruzik's freshman season with the
Michigan Wolverines was delayed due to the
COVID-19 pandemic in 2020. In her sophomore season, she hit 3.57 kills per set on .244 hitting with a career-high 2.52 digs per set, earning first-team All-Big Ten honors. She helped Michigan improve to 18–12 and qualify for the
NCAA tournament. She averaged 3.68 kills on .240 hitting with 2.34 digs per set in her junior season, repeating as first-team All-Big Ten, as Michigan went 17–13 and missed the
NCAA tournament. After three seasons in Ann Arbor, Mruzik transferred to the seven-time national champion
Penn State Nittany Lions in 2023. In her fifth season of eligibility, granted to college athletes because of the COVID-19 pandemic, she made 4.25 kills per set with career highs of 0.256 hitting, 2.37 digs, and 0.40 assists per set, earning first-team All-Big 12 and first-team All-American honors. She captained Penn State to finish the season 35–2, taking a share of the Big Ten regular-season title and winning the
2024 national championship, the program's eighth national title and first since
2014. In the national semifinals, she made a game-high 26 kills as Penn State pulled off a reverse sweep against
Nebraska. In the national title game, she tied her season high with 29 kills on .315 hitting, made 14 digs, and tied her career high with 5 blocks in a 3–1 win against
Louisville. She was named the tournament's most outstanding player. ==Professional career==