James Harden felt his performance was "all right" as the Houston Rockets belatedly began their season with a 128-126 overtime defeat to the Portland Trail Blazers.

After reporting late for the Rockets' preseason camp as news of his desire for a trade dominated headlines and spending a period in quarantine for violating the NBA's health and safety protocols, Harden scored 44 points as Houston got their campaign under way following the postponement of their opening game against the Oklahoma City Thunder.

The eight-time All-Star had just one preseason game under his belt yet looked anything but rusty during his 43 minutes on the floor for the undermanned Rockets, who had six players missing due to positive COVID-19 tests and contact tracing.

Harden became the first player in NBA history to post at least 40 points with at least 15 assists in their first game of the season.

It was the fourth time Harden has had that line in his NBA career and the 17 assists he finished with tied his career high. The only time he scored more with that many assists was when he combined them with 53 points and 16 rebounds against the New York Knicks in December 2016.

Asked to assess his performance, in which the 2018 MVP shot 12-of-22 from the floor and 6-of-13 from three-point range, Harden said: "It was all right.

"Too many turnovers but other than that… first game playing 40-something minutes I felt my conditioning could've been better obviously, but it was pretty solid. I think we let one get away from us.

"I didn't surprise myself at all. I know what I'm capable of.

"We showed a lot of fight. We came out with a great sense of urgency. You could just tell with it being the first game, basically playing eight players took a toll on us towards the end of the game.

"[We're] hopefully gonna finish this road trip strong, get back home and have our full roster."

Harden's fourth and final turnover of the game came on the last play of overtime, when he drove into the paint and threw the ball away before appearing to get frustrated with P.J. Tucker.

"I was just trying to make a quick decision," Harden explained. "As I got into the paint, they did a pretty good job of using their high hands, but I felt like I think it was P.J. on the block. If he would've crept in, he'd have had a layup.

"It would've been a tough shot to shoot over a couple guys, which I could have, but I'll watch the film and get better at it."