James Harden said he was "all over the place" on his return from injury but vowed to improve once he finds his rhythm for the Philadelphia 76ers.

The 2018 MVP winner was back in the starting line-up having missed 14 straight games after suffering a tendon strain in his right foot on November 2, with Philly going 4-5 in his absence.

However, his comeback failed to yield an upturn as the 76ers went down 132-123 to Harden's former team the Houston Rockets following double overtime.

Harden contributed 21 points but was just 4-of-19 from the field, missing all eight attempts inside the three-point arc. He also chalked up four rebounds and seven assists.

Philly coach Doc Rivers said Harden would be on a minutes restriction, but he still racked up 39. However, the 33-year-old said it was difficult to find fluidity.

"I didn't play well, but I've got to be better and I will," Harden said.

"I was all over the place. I'm not used to it, but I'm not making any excuses. I have to do better." 

Harden added that he had to fight his cause to play as much as he did in overtime.

"I had to fight to stay on the court just because there was a certain plan in place before the game started,'' Harden said.

"But once you go out there as a competitor you want to try to win."

The 76ers are on a three-match losing streak and sit seventh in the Eastern Conference with a 12-12 record. They next face the Los Angeles Lakers on Friday.