Dunn made 51 appearances with the Bulls during the coronavirus-shortened 2019-20 season in which the Bulls played 65 total games. The defensive-minded guard averaged 7.3 points, 3.6 rebounds, 3.4 assists and a career-best-matching 2.0 steals in 24.9 minutes per game, with 32 starts. Dunn shot a career-high 44.4 percent from the field, 25.9 percent from three and 74.1 percent from the free-throw line. Before the March sports stoppage, Dunn was fourth in the NBA in total steals (101), second in steals per game, first in steal percentage (3.8) and second in defensive box plus/minus (3.1). On Dec. 8 at Miami, Dunn scored a season-high 16 points to go with five boards and three steals. Arguably Dunn's best overall performance of the campaign occurred Jan. 8 against the Pelicans. In 31 minutes, Dunn posted 15 points (6-11 FG, 3-6 3Pt), seven assists, a career-best-matching five steals and four rebounds. Dunn accumulated 14 performances with double-digit points, 16 performances with at least five rebounds and 12 performances with at least five assists. He also had 20 games with at least three steals and 13 games with at least one block. In the 13 games that Dunn saw over 30 minutes, he averaged 11.5 points, 4.9 rebounds, 4.5 assists and 2.7 steals.

Dunn's 2018-19 season, his second with the Bulls, saw him start 44 of 46 games, a career high. He also continued to improve his free-throw accuracy, shooting 80 percent from the line. That marked a nice improvement his 74 percent mark as a sophomore and a drastic improvement over the 61 percent he drained as a rookie. Dunn's three point accuracy improved to 35.4 percent and his 30.2 minutes per game were also a career high. In the process, he averaged double-digit points (11.3) and more than four assists (4.1) for the second straight season. He also remained a major asset on the defensive end, averaging 1.5 steals and half a block per game. Unfortunately, knee and back injuries limited Dunn's availability at both the start and end of the campaign. Early in the season, Dunn missed 24 games due to an MCL sprain, then a Mar. 22 back injury forced the point guard to miss the final eight games of the season.

Dunn had a change of scenery in just his second NBA season, as the 23-year-old took the court for the Bulls after coming over in the offseason trade that sent Jimmy Butler to Minnesota. Dunn got a lot more playing time in the Windy City, as his minutes went up from 17.1 per night as a rookie to 29.3 in his first run with the Bulls. Unfortunately, a toe injury and a concussion limited the former No. 5 overall pick to just 52 games, 43 of which he started. He raised his numbers across the board in the expanded role, finishing with 13.4 points, 6.0 assists and 4.3 rebounds per game. Dunn also continued to be a pest defensively, doubling his steal rate to 2.0 per game. The increase in his production wasn't simply due to the larger volume, as he also increased his shooting percentage from 37.7 to 42.9. He went off for a career-best 32 points in a game against Dallas on Jan. 5, shooting 12-for-17 from the field. Dunn also recorded nine assists and four steals that night in what was likely his best overall effort of the season. The Providence product recorded 20-plus points nine times in all. He also had 10 or more assists five times, notching four double-doubles in the process.

After selecting Dunn fifth overall in the 2016 NBA Draft, the Wolves let the Providence College product acclimate slowly to the NBA, utilizing him mostly in a reserve role. Dunn played 17.1 minutes per contest, posting averages of 3.8 points, 2.1 rebounds, 2.4 assists and 1.0 steals in that time. On those occasions when he received extra time, Dunn showed plenty of potential. He approached a triple-double Jan. 22 against Denver, notching 10 points, eight boards and nine assists. Dunn delivered a season-high 17 points on 8-of-13 shooting in 28:47 against Portland on Mar. 25. But Dunn's finest effort for Minnesota came in the last game of the year, Apr. 12 against Houston. Starting for the first time since Nov. 9, Dunn racked up 10 points and an easily season-high 16 assists to go with a pair of rebounds, a steal and two blocks.