Finney-Smith appeared in 71 of a possible 75 games (68 starts) during his fourth season in the league, which was also his fourth with the Mavericks. He set career highs in points (9.5), rebounds (5.7), assists (1.6), threes (1.6) and blocks (0.5) per game. The forward also set career marks in field-goal percentage (46.6) and three-point percentage (37.6). Finney-Smith also ranked 20th in the league in offensive rating (122.0). In a Nov. 1 game against the Lakers, Finney-Smith racked up 10 rebounds, a season-high three steals and seven points. On Nov. 18 in a win over the Spurs, the Florida product had his first of three 20-point games, accumulating 22 points, five rebounds, three assists, one steal and one block in 35 minutes. Finney-Smith recorded his first of five double-doubles Nov. 24 in a win over the Rockets. In the victory, he posted 12 points, 10 rebounds, one assist, one steal and one block. On Feb. 26, in a six-point road win over the Spurs, Finney-Smith blocked a season-high three shots, plus added 14 points, four rebounds, two steals and one assist. During the Mavericks' opening seeding game in the bubble against the Rockets, Finney-Smith recorded a season-high five assists. He repeated that mark Aug. 8 in a win over the Bucks in which he also posted a career-high 27 points and a career-best six three-pointers. Between those matchups on Aug. 4, Finney-Smith grabbed a career-high 16 rebounds and scored 16 points in a win over the Kings. The versatile forward started all six Mavericks' playoff contests against the Clippers and averaged 10.2 points, 5.7 rebounds, 3.2 assists and 1.2 steals in 31.8 minutes per post-season match-up.

Finney-Smith's third NBA season represented a resurgence after injuries cost him much of the prior campaign. He played in a team-leading 81 games (26 starts) and set a new career high in minutes per game with 24.5. Finney-Smith also improved drastically as a shooter, blowing away his previous numbers in field-goal percentage (43.2) while also setting career bests in points per game (7.5), 3-point percentage (31.1), rebounds per game (4.8) and steals per game (0.9). For the third straight year, he shot north of 70 percent from the free-throw line, posting a 70.9 percent mark. On Nov. 2, the he scored a career-high 19 points off the bench against the Knicks. Finney-Smith grabbed a career-high 12 rebounds during an Apr. 7 victory over Memphis. On Apr. 9, the Florida product posted 15 points and 10 boards in a win over Phoenix. All in all, Finney-Smith collected three double-doubles among five games with double-digit rebounds. The defensive-minded forward racked up 18 games with two or more steals and eight games with at least two blocks.

A year after appearing in 81 games as a rookie, Finney-Smith played in just 21 games for the Mavericks in 2017-18 as he dealt with tendinitis in his left knee. When he was on the court, the Florida product played 21.3 minutes per night and made 13 starts. Finney-Smith managed 5.9 points, 3.6 rebounds and 1.2 assists per game, which were all new career highs. He shot 38.0 percent from the field and 29.9 percent from 3-point range. Finney-Smith was able to put together some impressive stat lines in his limited run, scoring in double figures five times and notching his first career double-double. That came Apr. 6 against the Pistons, when he scored a season-high 15 points and grabbed 10 rebounds. Finney-Smith grabbed five or more rebounds on six occasions. Encouragingly, the 24-year-old finished the season strong after missing so much time. He scored in double figures in each of the final four games of the campaign, averaging 13.3 points over 34.8 minutes per game in those contests.

Despite being overlooked in the 2016 NBA Draft, Finney-Smith went on to appear in 81 games for the Mavericks in his rookie season, starting 35 of those. He averaged 4.3 points, 2.7 rebounds and 0.6 steals across 20.3 minutes. Finney-Smith's best stretch of the year came in the first half of December. Over a nine-game span from Dec. 3 to Dec. 18, he scored in double digits five times, averaging 9.3 points per game on 51.7 percent shooting -- including 45.7 percent from 3-point range -- as well as 4.2 rebounds. That stretch concluded with his highest-scoring game of the year, a 17-point effort against Sacramento. The 6-foot-7 forward collected a season-high four steals Jan. 26 against Oklahoma City, stuffing the stat sheet with 11 points (including two threes), five rebounds, two assists and a block. A willing 3-point shooter all year long, the University of Florida product took 2.4 threes per game and connected on them at a 29.3 percent clip. He was efficient with his free-throw attempts, hitting 75.4 percent. Finney-Smith set a personal best with 11 rebounds against Phoenix on Apr. 9. All told, he notched five or more rebounds on 15 occasions.