Russell Westbrook expresses his excitement to join the Rockets and his gratitude for the city and people of Oklahoma City. (1:14)

HOUSTON -- Russell Westbrook offered something of a warning to the rest of the NBA regarding his reunion with James Harden.

"It's going to be scary, that's all I can tell you," Westbrook said during Houston Rockets media day Friday. "It's going to be scary -- not for us."

Seven years have passed since Westbrook and Harden last played together with the Oklahoma City Thunder in the 2012 NBA Finals. Harden and Westbrook, who have been friends since their childhoods in Los Angeles, have developed into perennial All-Star guards, and both have won an NBA MVP award.

But neither superstar has made it back to the NBA Finals since the Thunder's 2012 loss to the Miami Heat.

They pushed to reunite with the Rockets, who traded Chris Paul and a package of first-round picks to acquire Westbrook from the Thunder, in large part due to their desire to finally win a championship.

"We've accomplished a lot of individual accolades," said Harden, who led the league in scoring the past two seasons after Westbrook did so during his 2016-17 MVP season. "Now it's time to accomplish something together that we haven't accomplished before."

Some questioned the pairing of two of the league's most ball-dominant players, as Harden has elevated from a Sixth Man of the Year to perennial MVP candidate since he last played with Westbrook. Harden acknowledged that they would have to "figure it out" regarding ball distribution and how to complement each other offensively, but it's not a concern for him because of their friendship and mutual desire to win.

"If Russ got it going and Russ is having one of those games that we've all seen before, guess what I'm going to do: sit back and watch the show, and vice versa," Harden said. "It's just a part of basketball. So you can't sit up here and say, 'Oh, Russ is going to have the ball for the first half and I'm going to have the ball the second half.' No, things happen through the course of the game that you just flow with and go with.

"All of us in this locker room and this front office has one goal, and that's to win it. However that happens, it's going to happen, and we're just going to figure it out."

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The process of figuring it out could be limited in the preseason by Westbrook's availability as he continues to recover from the arthroscopic knee surgery he had after the Thunder were eliminated in the first round of the playoffs last spring.

Coach Mike D'Antoni said Westbrook was only recently cleared for 5-on-5 work. The Rockets intend to proceed cautiously with Westbrook, who is likely to sit out some practices and preseason games.

"I feel like I'm in a good place," Westbrook said of his health. "I'll be ready to go on opening night."

The Rockets are optimistic that Westbrook, one of the game's premier penetrators, will greatly benefit by playing in D'Antoni's wide-open offensive system while being surrounded by the kind of perimeter shooters that recent Thunder teams have lacked.

Houston general manager Daryl Morey noted that guards historically have had career years playing for D'Antoni then chuckled when he added that it would be difficult for Westbrook considering his previous production. Houston also anticipates that Westbrook, the best rebounding guard in the league, will provide a turbo boost for a team that ranked 27th in pace last season.

"James Harden is, like, the best half-court player I've ever seen, honestly," Morey said. "And then Russell is maybe the best transition player, one of the best of all time, as well. If you put those things together, which I think we have a chance to do, now you've got something really special. We'll see how it all works out, but I think it could be really special."

D'Antoni plans to stagger the minutes of his star guards, as he did with Harden and Paul. He expects Westbrook to rest about 16 minutes per game and Harden about 13 per game, so they might play together for only about a quarter and a half.

That will include crunch time, with D'Antoni citing the final five minutes of games as the "most important thing" the Rockets need to figure out about the Harden-Westbrook dynamic. But D'Antoni emphasized that he will not ask Westbrook to drastically alter his playing style.

"It'll work itself out. You try not to overcoach it," D'Antoni said. "We need Russell to be Russell. We don't want to change him. He's an MVP. That's who we need. We need his bravura to be Russell. That's good enough."

Skeptics of the fit focus on how Westbrook, a career 30.8% 3-point shooter, will affect the Rockets' offensive spacing when he is playing off the ball. Westbrook waved away those worries by saying that he impacts the game in many ways.

"I don't have to have the ball to impact the game," said Westbrook, who has averaged triple-doubles in each of the past three seasons. "I don't have to score, I don't have to do anything. I can defend, I can rebound, I can pass, I can lead. Our main goal, main focus, is to win. I can go be scoreless, and if we win, that's the best thing that ever happened. That's all I cared about, and that's all I ever cared about.

"When it comes to me and James playing together, who's going to have the ball, who's not going to have the ball, it really doesn't matter. I don't have to prove I can score 30 points. I've done that before. I don't have to prove to average 10 assists. I've done that before. I don't have to prove to get 10, 11 rebounds. I've done that before. My goal is to win a championship, so whatever it takes to do that, that's what I'm going to do."