Harden, after the longest layoff of his career, had 18 points, 11 assists and seven rebounds as the Nets outlasted the Spurs 128-116. Landry Shamet scored 21 points and Nicolas Claxton had a career-high 18 for the Nets, who won their third straight and pulled within 1½ games of Philadelphia for the Eastern Conference lead.
"I study the game. I'm very unselfish. I take the game and I play the right way every single night," Harden said after logging 26 minutes. "So, I don't try to do anything that I can't do, or anything that doesn't benefit our team. And that mindset right there keeps me in a really good place."
While Harden returned, the Nets had to wait, again, to see their Big Three in action: Kyrie Irving did not play Wednesday because of a facial contusion suffered the night before.
The decision for Harden to play was made minutes before he warmed up at Barclays Center on Wednesday evening. Harden did not start and was on a minutes restriction. It was the first time Harden came off the bench for a regular-season game since April 2012.
"That sixth man role," Harden said. "I've mastered that, as well. You know, I've got an award for that role. That role is easy, coming out and impacting the game. Doing whatever it takes to win -- whether it's offensively or defensively."
It was clearly important for him to fine-tune his game for the playoffs.
"Preseason is one thing. The regular season is another level. The postseason is an entire another level," Harden said. "The levels increase as you go different rounds, too. For me, I wanted to get out there and just be on the court, let them feel my presence and also get my conditioning and my wind back up, and be effective on both ends of the ball for an extended period of the game."
Nash has limited minutes for stars coming back from extended absences before. Kevin Durant came off the bench earlier this season when he returned from a hamstring strain. At the time, Nash said that because Durant was on a minutes restriction, he wanted to ensure Durant would be available to close the game in the event the Nets needed him to pull out a win in a tight contest.
Irving, meanwhile, was injured in the third quarter of the Nets' game against Chicago on Tuesday night when he went up for a rebound and Nikola Vucevic inadvertently elbowed Irving in the face. Irving has been cleared of a concussion, Nash said.
Nash added that because he has been cleared, Irving will be able to play in the Nets' remaining two games if he is feeling well enough.
"It's a matter of how comfortable he is playing," Nash said. "And if they get that time together, it would be great. If they don't, they don't."
The Nets' three stars -- Irving, Harden and Durant -- have played in just seven games together this season. Harden, who last played on April 5, has missed the Nets' past 18 games. After making progress on the injury, Harden suffered a setback in his rehab on April 19, further delaying his return.
The Nets on Wednesday were also without Joe Harris, who has a sore left hip. It was the first game Harris has missed this season.
The Nets have played 38 total games with two of their three superstars -- and only two of those are with just Durant and Harden. Wednesday marked the second time Durant has played in both games of a back-to-back this season.
Nash said that while health is the most important thing to him heading into the playoffs, if all three All-Stars get a chance to play together, it could aid the team down the line.
"If they can form any sort of cohesion or speed up that process, that's great," Nash said. "But we recognize there's no perfect solution here. They're not going to be totally formed and cohesive on one or two games. But could it help? Sure. But I think more than anything, it's about them continuing to build their level and their confidence and their rhythm going into the playoffs."