The Suns dropped to 1-4 with Saturday's 117-96 loss at Memphis and they will be playing their first back-to-back of the season. The Thunder haven't played since Thursday.
But the Thunder could be without its biggest star.
Russell Westbrook, who sat out the season's first two games after offseason knee surgery, missed Saturday's practice with a sore shoulder.
"I think he'll be fine," Thunder coach Billy Donovan said of Westbrook's availability, but said he wouldn't know for sure until Sunday.
Westbrook is averaging 22.5 points, 13.5 rebounds and eight assists in two games.
Oklahoma City isn't the only team that could be without its best player, though.
Phoenix's Devin Booker missed the loss to Memphis after leaving Wednesday's loss to the Los Angeles Lakers with a hamstring injury in the third quarter.
"I don't know much about the injury, it's my first time I've ever done anything to it," Booker told reporters Friday.
The Thunder are expecting Booker to be available.
"He's a guy that we have to have eyes on the whole game, a guy we have to make uncomfortable out there, a guy we have to make sure we play without fouling and play him physical," Thunder forward Patrick Patterson said. "He comes off a lot of screens, he gets up a lot of shots, he's a tremendous scorer, he's a tremendous piece for their team when it comes to winning."
Booker is leading the Suns in scoring with 27.8 points per game. That is 10 points per game better than their second leading scorer, top pick Deandre Ayton, who had a season-high 24 points against the Grizzlies.
Josh Jackson started in Booker's place Saturday night, scoring eight points on 3-of-10 shooting and turning the ball over six times in the first quarter.
The Suns have struggled to score in transition, and the game in Memphis was no different.
"It just goes back to -- we can't play just hard," Suns coach Igor Kokoskov said. "We follow (the) game plan, we execute (the) game plan, but we couldn't convert those. The whole game looks different when you convert.
"We had a couple of easy points in transition and convert those points, it releases a little bit of pressure from our half-court offense."
During the Thunder's 0-4 start, they have been the worst shooting team in the NBA.
Oklahoma City was one of the top 10 offenses in the league a year ago, but so far this season the Thunder are shooting just 39.1 percent from the field, 24.1 percent from the 3-point line and 64.3 percent from the free-throw line - all worst in the NBA.
The Thunder also have a league-low 81 assists.
Donovan isn't as concerned about the lack of ball movement as getting Oklahoma City's offense back to hitting shots.
"The more passes you have doesn't necessarily mean you shoot the ball better because the metrics say the deeper you get into the clock, the worse you shoot," he said.