OAKLAND -- With Jermaine O'Neal out, the Warriors need Marreese Speights to deliver.

After a slow start this season, Speights, a backup power forward, has begun to do just that. He played with renewed vigor in Tuesday's win over the New Orleans Pelicans, reaching double-digit scoring for the second time in the last three games, with 12 points.

With the San Antonio Spurs visiting Oracle Arena on Thursday, the Warriors could use more of the same.

"He's done a really good job of focusing in the last couple of games," swingman Andre Iguodala said of Speights. "Just putting his hard hat on and understanding that he has to pick up some of the areas that Jermaine was really impactful for us, especially with rebounding the ball and sprinting down the floor.

"Defensively, he's getting better. We know he has a world of talent, and he's getting ready to go out there and show it."

For Speights, a 6-foot-10 former Florida star in his sixth NBA season, the better results stem from an improved work ethic.

"I feel way better out there on the court now," said Speights, who is averaging 11.0 points and six rebounds over the past three games. "I feel more confident, and my wind is getting better."

Warriors coach Mark Jackson said Speights' recent play is "what we needed." He has appreciated Speights' drive behind the scenes as well.

"He's working extra hard, putting in the time, coming in early, leaving late, and he's getting results because of it," Jackson said. "So, I'm very pleased with the way he's playing right now. With the absence of Jermaine we needed him to step up his game, and to his credit he has."

Speights gives Jackson credit for believing in him.

"He's always given me opportunities since I got here," said Speights, a 2008 first-round pick by the Philadelphia 76ers. "A lot of that has got to do with coach trusting me and giving me a chance to go out and prove myself."

O'Neal, 35, in his 18th NBA season, could be out for a prolonged period after undergoing arthroscopic surgery for a torn ligament in his right wrist.

Speights appears ready to hold down the fort until he returns.

"I got to make sure I hold it down until he gets back, so we can play together," Speights said.