Prior to the All-Star break, Capela appeared in 39 games for the Rockets. He averaged 13.9 points and a career-best 13.8 rebounds per game. Capela provided strong defensive numbers, as well, averaging 1.8 blocks and 0.8 steals per contest. The center also registered three 20-point, 20-rebound, two-block performances. On Feb. 5, Capela was part of a four-team trade that sent him from the Rockets to the Atlanta Hawks. Due to a plantar fascia injury, Capela did not suit up for the Hawks prior to the suspension of the 2019-20 NBA season on Mar. 11.

Capela played well in 2018-19, the first season under his new contract. The fifth-year center averaged career highs in points (16.6), rebounds (12.7) and assists (1.4) per game while shooting 64.8 percent from the floor. That lofty field-goal percentage ranked second in the Association after he led the league in that category the year before. He also averaged 1.5 blocks per game, the second-highest mark of his career, with a season-high five rejections Dec. 17 against Utah. Capela appeared in 67 games and logged a career-high 33.6 minutes per contest. On Jan. 7, Capela scored a career-high 31 points, adding nine boards in a home win over Denver. One week later, he suffered a thumb injury that forced him to miss 15 games. The center ended the season with 45 double-doubles, five games with at least 20 rebounds, and three contests with at least 20 points and 20 rebounds. Capela recorded double-digit rebounds for 20 consecutive games from March 10 to April 20, a span that included three postseason contests. He started all 11 of Houston's playoff games, averaging 9.7 points, 10.3 rebounds and 1.1 blocks per postseason contest.

Capela posted new career highs in nearly every category in his fourth NBA season. The Rockets' starting center averaged 13.9 points, 10.8 rebounds and 1.9 blocks over 74 games while shooting 65.2 percent from the field. In fact, Capela's marksmanship from the field was tops in the NBA. Never was that more evident than Dec. 11 against the Pelicans, when he poured in a career-high 28 points on 13-of-14 shooting. The Swiss big man recorded an impressive 42 double-doubles on the season and had two 20-rebound performances. He scored 23 points and pulled down a career-high 25 boards in a win over the Nuggets on Feb. 9. That outburst began a season-high streak of five consecutive double-doubles. During that stretch, Capela averaged 18.2 points and 14.0 rebounds on 66.7 percent shooting. Capella's Rockets again posted a strong record, finishing the season at 65-17, defeating the T-Wolves and then the Jazz in the first two rounds of the playoffs. As he had in the regular season, Capela started every postseason game for Houston. Across 17 playoff contests, the 6-foot-10 center averaged 12.7 points, 11.6 rebounds, and 2.1 blocks.

The 2016-17 season was a breakout campaign for Capela, who became a regular in Houston's starting lineup and saw his stats skyrocket accordingly. He played in 65 games, making 59 starts, and averaged career highs with 12.6 points and 8.1 rebounds per contest while tying the previous season's mark with 1.2 blocks per game. On Nov. 19, Capela scored a career-high 20 points in a win over the Jazz. On Nov. 27, the young center bested that mark with 21 points in a road win over Portland, adding eight rebounds and five dimes. But Capela's season hit a speed bump when he was forced to leave a game Dec. 17 due to what was originally diagnosed as a bruised left leg but turned out to be a broken fibula. The injury ultimately cost Capela 15 games. However, he returned to his pre-injury form soon after returning. In his third game back, a Jan. 20 loss to Golden State, the young center scored 22 points and grabbed 12 boards. He ultimately eclipsed that scoring mark again with a season-high 24 points and 11 boards Mar. 4 against Memphis. For the season, Capella delivered 15 double-doubles and shot 64.3 percent from the field, which ranked third in the NBA. The Swiss center started all 11 postseason games for the Rockets, delivering 10.5 points, 8.7 rebounds and 2.5 blocks per playoff contest. He posted three double-doubles in the playoffs, including a 20-point, 13-board effort in Game 1 of the second round against San Antonio.

After spending his rookie regular season mostly in the D-League, Capela stepped into a far more substantial role for the Rockets in 2015-16. He played in 77 games for the Rockets, starting 35 of those and averaging 19.1 minutes per contest. On Nov. 6, Capela recorded his first career double-double with 13 points, 12 rebounds and four blocked shots during a win at Sacramento. The young Swiss center ultimately delivered 10 double-doubles on the season. One of those came Nov. 19, when Capela scored a career-high 18 points alongside 11 rebounds during a road win over the Knicks. On Apr. 13, the big young center grabbed a career-best 17 rebounds and three blocks in a home win over the Kings. Capela notched eight games with three or more blocks, including blocking four shots on four occasions. Ultimately, his sophomore season in the Association saw Capela produce per-game averages of 7.0 points, 6.4 rebounds and 1.2 blocks per contest. He appeared in all five games of the Rockets' playoff games, grabbing 12 rebounds in Game 1 of the series.

Capela was picked in the first round (25th overall) by the Rockets in the 2014 NBA Draft. The Swiss native played professional ball in the French LNB Pro A league before joining the Rockets. He split his rookie season on the west side of the Atlantic Ocean between the Rockets and the D-League's Rio Grande Valley Vipers. Capela appeared in 38 games with the Valley Vipers and 12 contests with the parent Rockets. He made his NBA debut on Nov. 6 with six minutes of run that led to three rebounds and one assist in a win over the Spurs. In the D-League, the rookie averaged 16.1 points, 9.7 rebounds and 3.0 blocks over 25 minutes per contest. On Feb. 25, Capella grabbed a D-League career-best 12 rebounds in a win over Maine. On Mar. 25, Capella scored a D-League career-high 35 points along with 15 rebounds and six blocks in a loss to the Legends. Capela blocked six shots in six separate D-League games. Back in Houston, Capela played in six of the Rockets' last nine games. He posted his best regular-season game Apr. 13 in a win over the Hornets, producing 10 points, five rebounds and a block. He then enjoyed a regular rotational role for the Rockets in their run to the Western Conference Finals, playing in all 17 of their postseason games. Capela averaged 3.4 points on 67.7 percent shooting in the playoffs, adding 2.5 rebounds and 0.5 blocks per game.