Zion Williamson must not go prolonged stretches in the fourth quarter without touching the ball, fumed New Orleans Pelicans coach Alvin Gentry after their 117-109 loss to the Houston Rockets.

The Rockets triumphed at Toyota Center on Sunday, with James Harden pouring in 40 points as Houston came from behind in a fourth quarter that saw the Pelicans score just 16.

Williamson, the first overall pick in the 2019 NBA Draft, was making his sixth appearance in the league, having undergone right knee surgery in October.

The 19-year-old forward has quickly proven himself to be a force to be reckoned with, though, and logged 21 points and 10 rebounds against Houston.

However, Gentry was irate his team failed to find Williamson more regularly as they fell away in the final period and blamed himself.

"We didn't execute and we didn't do what we were supposed to do. That being said, Zion can't go four minutes without touching the basketball and that's on me," said Gentry.

"That's something that I've got to make sure that will never happen again. So I take responsibility for that. And if we're not gonna get it to him and not gonna execute, then we've got to have different people in the game. That's on me also."

Gentry denied the suggestion it was down to a lack of chemistry with Williamson still in the early stages of his rookie season, while also criticising the "absurd" and "ridiculous" total of 21 turnovers from his team.

"You've got to throw [Zion] the damn basketball, it has nothing to do with playing together or figuring it out," said Gentry.

"He has advantage and we've got to find a way to get him the basketball better, so I'm not buying the playing together or figuring out or anything like that. We have to have him have touches in the fourth quarter, if not there's no reason for us to have him in the game. And that's not going to happen either.

"I like our chances when he's got it down there because I think he's going to make the right play, and we didn't do that. You can't have 30 points off your turnovers and think you're going to beat a good basketball team.

"You can get away with it every now and then, but we're shooting 64 per cent for most of the first half and we're trailing in the game and so that just tells me that what we were doing as far as execution and turning the ball over is absurd, it is just ridiculous. It really was. It's as disappointed as I've been this year from the standpoint of doing what we're supposed to."

Harden was impressed by Williamson after his first game against the Duke product. Asked for his assessment of the Pelicans star, Harden told ESPN: "Beast.

"He's gonna be really good. This is only like his 10th game playing, he has a feel for the game, obviously he's strong, so he's gonna be great.

"He's really good. Very, very explosive. Athletic, as we all know. He has a good feel for the game."