McQuaid averaged 3.5 points and 1.6 assists per game as a freshman. He worked on quickening his shot release and correcting his footwork. Prior to his sophomore season, McQuaid had double hernia surgery. He averaged 5.6 points and 1.9 rebounds per game while shooting 35.3 percent from behind the arc. On November 23, 2017, McQuaid scored a season-high 20 points against DePaul on six of eight shooting from behind the three-point line. As a junior, he averaged 6.0 points and 1.9 rebounds per game. McQuaid suffered a thigh bruise in the final of the Las Vegas Invitational against Texas and missed several games in late November and early December 2018. McQuaid scored 27 points in a 65-60 win over Michigan in the Big Ten Tournament final. As a senior at Michigan State, McQuaid started 35 of 39 games, averaging 9.8 points and 3.0 rebounds per game while shooting 42 percent from behind the arc. He helped the Spartans finish 32-7 and reach the Final Four of the NCAA Tournament. McQuaid was an honorable mention All-Big Ten selection by the media and coaches and was selected to the All-Defensive Team, as well as earning the team's John E. Benington Defensive Player of the Year Award.
