After beginning his professional career, he sought Lithuanian citizenship and played for the Lithuania men's national basketball team.

[1] His family emigrated to Chicago before moving to Winnipeg and Etobicoke (where he started to play basketball at the age of six) before settling in Oakville, Ontario.

[10] After accumulating offers from several schools including Baylor, Cal, Illinois, Oklahoma, Oregon, Tennessee, and USC and rankings of number 66 overall and 16 small forward at 247sports.com, Brazdeikis announced that he would officially visit Michigan, Vanderbilt and Florida on September 8, 15 and 29, 2017, respectively.

[13] He signed a National Letter of Intent with Michigan on November 10, 2017, along with the 2018 class that included Colin Castleton, David DeJulius, Brandon Johns, and Adrien Nunez.

[14][15] In Michigan's November 6, 63–44 victory over Norfolk State, Brazdeikis debuted with 12 points in head coach John Beilein's 800th career win.

[18][19] On November 18, Brazdeikis helped Michigan defeat Providence 66–47 to win the Hall of Fame Tip Off tournament with a game-high 20 points and another 7 rebounds.

[22][23] Brazdeikis posted his third consecutive 20-point game on November 28, as Michigan defeated (#11 AP Poll/#13 Coaches Poll) North Carolina 84–67 in the ACC–Big Ten Challenge behind his career-high 24 points.

[38][39] On January 3, Michigan returned to Big Ten play with a 68–55 victory over Penn State powered by Brazdeikis' first career double-double (16 points and a career-high 11 rebounds).

[40][41] On January 9, Brazdeikis was one of 7 Big Ten athletes included on the John Wooden Award Men's Midseason Top 25 watchlist.

Michigan jumped out to a 17–0 lead and its defense allowed only 18 points in the first half, as Indiana shot a season-low 27.6% from the field during the game.

[51] On January 28, Brazdeikis earned his fourth Big Ten Freshman of the Week recognition for his performances against Minnesota and Indiana.

[52] On February 5, Brazdeikis was one of four Big Ten athletes named to the Wooden Award Late Season Top 20 Watch List.

[54][55] On February 7, Brazdeikis was one of two Big Ten athletes (along with Jordan Murphy) named a Karl Malone Award Top 10 finalist.

[57][58] On March 12, the U.S. Basketball Writers Association named Brazdeikis to its 2018–19 Men's All-District V (OH, IN, IL, MI, MN, WI) Team, based upon voting from its national membership.

[65] Following the season, on April 9, Brazdeikis, along with teammates Jordan Poole and Charles Matthews, declared for the 2019 NBA draft with the intention of hiring agents.

[87] On July 24, 2022, Brazdeikis returned to his homeland and signed a two-year (1+1) contract with Žalgiris of the Lithuanian Basketball League (LKL) and the EuroLeague.

[93] Brazdeikis earned a silver medal with Team Canada at the 2015 FIBA Americas Under-16 Championship, averaging 9.2 points and 7.2 rebounds per game.

[7] He was invited to participate in the April 13, 2018, Nike Hoop Summit[9] and recorded nine points, four rebounds and three assists in 12 minutes of play during the 89–76 World team's victory.