Houston Rockets point guard Kevin Porter Jr. lost his temper during a heated halftime discussion and didn't return to the court, leaving the Toyota Center during the second half of Saturday's 124-111 loss to the Denver Nuggets, sources told ESPN.

Porter became upset after assistant coach John Lucas challenged him, revisiting an issue that led to Porter losing his composure on the bench during the first half, sources said.

The Rockets, who trailed 77-55 at halftime of their seventh consecutive loss, did not return to the court until moments before the third quarter began.

"We had a spirited debate," Rockets head coach Stephen Silas said during his postgame media availability. "I have certain demands of this team as far as playing hard. ... I wasn't satisfied with the effort."

The Rockets announced during the second half that Porter was questionable to return due to his left thigh being evaluated. Porter has been bothered for weeks by a left thigh contusion, causing him to miss several games, but that was not the issue that led to his absence after halftime, according to sources.

Silas did not mention Porter specifically during his postgame comments.

Center/power forward Christian Wood, the Rockets' leading scorer this season, did not start Saturday night due to breaking a team rule, Silas said. Wood played eight scoreless minutes in the first half, during which Houston was outscored by 17 points, and did not play in the second half.

"Coach's decision," Silas said of Wood sitting out the second half.

A source said that potential discipline, if any, for Porter has yet to be determined.

The Cleveland Cavaliers traded Porter to the Rockets last January for a top-55-protected second-round pick after deciding to move on from their former first-round pick due to off-court issues, which led to Porter being inactive for the beginning of the 2020-21 season. The Cavaliers announced their intention to trade or release Porter, the No. 30 overall pick in the 2019 draft, after he exploded on team officials over them moving his locker to an auxiliary area. The Cavaliers had given his locker to Taurean Prince, who had arrived with Jarrett Allen as part of the four-team James Harden trade. Porter Jr. showed up to the arena for the first game of the season when he discovered his locker had been moved.

Houston sent Porter to its G League affiliate to ease his transition to the Rockets, who moved him from wing to point guard. Porter, 21, has had some success in Houston, averaging 15.0 points and 6.1 assists per game over the last two seasons.