In his freshman season at Northeastern, Walker shared the backcourt with Jordan Roland.[5] On January 2, 2020, he scored a season-high 32 points in a 77–68 win over Elon.[6] As a freshman, Walker averaged 10.4 points, 3.4 assists and 1.8 steals per game, earning Colonial Athletic Association (CAA) All-Rookie Team honors.[4] He was named CAA Rookie of the Week four times.[7] On February 13, 2021, Walker scored a sophomore season-high 36 points in a 76–67 win over Towson.[8] He averaged 18.8 points, 4.8 assists, and 2.4 steals per game as a sophomore, earning First Team All-CAA and Defensive Player of the Year recognition.[9][10] Walker led the CAA in scoring during conference play and in steals.[11] After his sophomore season, Walker transferred to Michigan State.[12][13] He chose the Spartans over Maryland, Kansas, Texas, Miami (Florida) and Vanderbilt.[4]
Michigan State
During his junior season, Walker split time at point guard with A. J. Hoggard, though Walker was the better shooter of the two.[14] On December 8, 2021, he scored 15 points and had five rebounds and three assists in a 76–67 win against Minnesota.[15] On February 26, 2022 against Purdue, he hit a go-ahead three pointer with 1.4 seconds left to give Michigan State a 68–65 lead. They would end up holding on and winning the game. Walker averaged 8.2 points and 4.3 assists per game, shooting 47.3 percent from three-point range.[16] As a senior, Walker averaged 14.8 points and 2.8 assists per game, earning Second Team All-Big Ten honors.[17] He opted to return for his fifth season of eligibility.[18] On March 8, 2024, Walker hit the 2,000-point milestone in a 53–49 win over Northwestern.[19]