An undrafted rookie last season, Garrett played in only 12 games due to bad injury luck that doesn't seem to have subsided. Miami coach Erik Spoelstra said it would be a "business decision" whether Garrett is kept on the roster.
Marcus Garrett was born in Dallas, Texas in November of 1998. Garrett grew up prioritizing football over basketball but quit after breaking his leg in sixth grade. His uncle, a former San Diego State basketball player, started coaching Garrett from a young age. In eighth grade, Garrett joined a local AAU team (Swag House). Garrett played high school basketball for Skyline High School in Dallas. During his senior year he averaged 17.3 points, 10.4 rebounds, 9.1 assists, 3.1 steals and 2.9 blocks per game, carrying his team to the Class 6A semifinals. He was awarded the Texas Gatorade Player of the Year award and was rated a four-star recruit which put him among the top-ranked Texas prospects in the 2017 class. Garrett committed to play for Kansas despite offers from in-state powerhouses Texas and Baylor. At Kansas, Garrett was named to the Big 12 All-Defensive Team as a Sophomore. As a junior, he started all 31 games averaging 9.2 points, 4.7 assists, 4.5 rebounds and 1.8 steals per game. He was named Big 12 Defensive Player of the Year in 2020, All-Defensive and Third-team All-Big 12 honors, and the Naismith Defensive Player of the Year. After his senior season at Kansas which he averaged 11.0 points, 4.6 rebounds, 3.7 assists and 1.6 steals per game, he declared for the 2021 NBA draft. Garrett went undrafted and signed a two-way contract with the Heat after a breakout performance for the Heat during Summer League.