Montrezl Harrell was selected by the Houston Rockets in the second round (32nd overall pick) during the 2015 NBA Draft. He played 39 games with the Rockets in his rookie season, averaging 9.7 minutes per contest. In his NBA debut, Harrell scored eight points and made all four of his field-goal attempts against Denver on Oct. 28. On the season, the 6-foot-8 forward posted per-game averages of 3.6 points and 1.7 rebounds. He scored a season-high 17 points against Golden State on Oct. 30, adding three boards. On Jan. 17, he scored 10 points and grabbed a season-best eight rebounds in a win over the Lakers. Harrell spent parts of the season in the D-League with Rio Grande Valley. In 12 games with the Vipers, he posted per-game averages of 24.3 points, 9.3 rebounds and 2.4 blocks. Harrell also appeared in two postseason contests with the Rockets during the first round of the playoffs against Golden State. In those games, he totaled three points and two rebounds across 12 minutes.

Harrell's role grew larger in his second season with Houston. He played in 58 games and averaged 18.3 minutes per contest, nearly doubling his average playing time over his rookie campaign. Consequently, Harrell posted across-the-board improvements in points (9.1), rebounds (3.8) and assists (1.1) per game. After shooting 64.4 percent from the field as a rookie, Harrell raised that number to a stellar 65.2 percent in his sophomore campaign. He also shot 62.8 percent from the charity stripe, nearly 10 points higher than in his previous season. On Dec. 30, he scored a career-high 29 points in a win over the Clippers. He nearly matched that mark nine days later, scoring 28 points in a victory over Toronto. He posted the first double-double of his career against Golden State on Dec. 1, totaling 13 points and 10 rebounds. Harrell saw limited action in the postseason, playing in five games as Houston advanced to the Western Conference Semifinals. In the playoffs, he racked up five points and six rebounds in a combined 21 minutes of action.

In Harrell's first season with the Clippers, he saw a huge increase in games played, up to 76 games from his previous 58. Most of his numbers across the board improved, including 309 more points and 88 more rebounds. His offensive efficiency continued to stay at a high mark; Harrell shot 62.6 percent from the floor, trailing only starting center DeAndre Jordan among players who saw over 15 minutes per game on the team. However, Harrell outperformed Jordan in points, blocks and steals per 36 minutes. Harrell also was 11th in the league in offensive rating, eighth in true shooting percentage and third in effective field-goal percentage. His hustle plays, epitomized through actions such as running the floor, rebounding and scoring around the rim (115 dunks), made him an invaluable member of the second unit. Harrell was able to achieve this despite being undersized for his position at 6-foot-7. To cap it off, Harrell posted a career-high Player Efficiency Rating of 24.7, far surpassing the league average of 15 and placing him in competition with All-Stars like Russell Westbrook, Karl-Anthony Towns and Chris Paul. Harrell had an impressive March in which he scored 20 or more points on four occasions. This stretch was highlighted by his season-best game of 24 points, seven rebounds, three assists, two blocks and a steal against the Trailblazers in only 20 minutes.

In his second season with the Clippers, Harrell demonstrated significant improvement, with increases in points (16.5), rebounds (6.5), and assists (2.0) per game. One of his best performances of the season came early, on Oct. 26, when he posted 30 points -- including hitting 14-of-15 free throws -- to go with six rebounds, two steals, and two blocks. The big man would then go on a run of 14 contests with at least 10 points and six boards, with six double-doubles over that span. Harrell enjoyed another solid stretch around the holiday season, averaging 18.2 points, 7.9 rebounds, 1.1 steals, 1.3 blocks, and a 62.7 field-goal percentage across 12 appearances between Dec. 22 and Jan. 14. During that same span, Harrell had a pair of 30-plus-point performances, highlighted by a season-high 32 points against the Mavericks on Feb. 25. Harrell continued to play well in a Round 1 playoff series against the Warriors, averaging 18.3 points per game on 73.1 percent shooting across six games. His best effort of the series came in Game 2, when he posted 25 points -- including a perfect 9-for-9 from the line -- to go along with 10 rebounds in a 135-131 road victory. Harrell finished the season ranked 17th in the league in blocked shots per game (1.3), 18th in PER (23.4), ninth in true shooting (63.6%), and fifth in field goal percentage (61.5%). He finished third in the voting for the Sixth Man of the Year award and seventh in the voting for the Most Improved Player award.