In his first season with the Spurs, Bates-Diop played in 30 games, averaging 8.2 minutes per contest. The Ohio State product finished with per-game averages of 2.6 points, 1.6 rebounds, 0.4 assists and 0.4 steals. On a per-36 minutes basis, those numbers translated to 11.6 points, 7.2 boards, 1.8 assists and 1.6 steals. The forward made 44.8 percent of his field-goal attempts and 66.7 percent of his free-throw tries. Over his final two contests, he averaged 20.5 minutes, 8.5 points and 6.0 rebounds per game. On Feb. 24, he scored a season-high nine points against Oklahoma City. In that contest, he also registered a career-best four steals. Bates-Diop tied his season high by scoring nine points in only 12 minutes versus Phoenix on May 16.

Bates-Diop opened his sophomore season with the Timberwolves, appearing off the bench 37 times before being moved to Denver in a four-team deal that occurred Feb. 5. He went on to appear in seven more games for the Nuggets to close out the 2019-20 regular season, with five of those coming during seeding play in the Orlando bubble. He also spent four games in the G League, seeing extensive playing time and posting composite averages of 18.0 points and 6.3 rebounds while averaging 3.0 made threes per game. Back at the NBA level, the Ohio State product posted double-digit scoring efforts on 14 occasions. His best game of the year came Nov. 23 with the Wolves, when Bates-Diop saw a season-high 37:06 of court time and responded with 22 points, a new career high. Four days later, Nov. 27 versus the Spurs, he posted his second-highest-scoring game of the year, a 16-point effort in which he made a career-high four three-pointers on six attempts. With the Nuggets, his biggest output came on the season's final day, when he turned 24:21 of court time into 11 points, six rebounds, two blocks and a steal. Bates-Diop went on to appear five times during the Nuggets' 19-game postseason run to the Western Conference Finals.

Bates-Diop joined the Timberwolves after they selected him with the 48th pick in the 2018 NBA Draft. The Ohio State product started three times in his 30 appearances, which were largely concentrated toward the end of the season. All told, Bates-Diop averaged 16.8 minutes, delivering 5.0 points, 2.8 rebounds 0.6 steals and 0.5 blocks per game. On Mar. 10, Bates-Diop started and scored a career-high 18 points to help defeat the Knicks by a 103-92 score. Two days later, he dished out a season-high four assists against the Nuggets. His biggest minutes came in an overtime victory over the Wizards on Mar. 9, when he played 36:30, recording 12 points, five rebounds and a steal. The rookie also spent time with the Iowa Wolves of the G-League, where he started 16 games while averaging 17.7 points and 8.8 rebounds.