PHOENIX — The Nets’ surprising start is in danger of being short-circuited. They are expected to lose their leading scorer for the better part of a month.

Cam Thomas has been diagnosed with a left hamstring strain after undergoing an MRI exam Tuesday.

The young guard, averaging a team-high 24.7 points, won’t be evaluated for three weeks in a loss that will hurt Brooklyn.

“It does. That’s a reality,” Jordi Fernandez said. “Those are guys that have done a great job for us, and we’re going to miss him. With that being said, it is what it is. We’re going to move on now, play this game, fight, compete and find a way.

“And this group has done it. C.T. didn’t play towards the end [at Golden State]. He didn’t play the Charlotte game. We’ve had experience [without him]. Do we always want him with us? Yes. We want him healthy at 100 percent, or 200 percent. If he’s not there, we’ll figure it out and we’ll fight.So that’s been part of the identity of this group is next-man-up, and go out there and fight.”

Starting center Nic Claxton (lower back injury management), Noah Clowney (sprained left ankle), Day’Ron Sharpe (left hamstring), Bojan Bogdanovic (left foot injury recovery) and Jaylen Martin (knee) were all out for the Nets who still pulled out a 127-117 win over the Suns on Wednesday.

Dorian Finney-Smith (left ankle sprain) was questionable, but finished with nine points and a steal in 32 minutes. Cam Johnson (right ankle sprain) and Ben Simmons also played, but Jalen Wilson (calf) did not.

Despite the win over the Suns, Thomas’ loss will hit the Nets hard.

The Nets are now a surprising 9-10, and Thomas has been a huge part of that. He’s averaging career-highs in scoring, assists (3.4), shooting percentage (46.1) and 3-point percentage (38.9). He also improved his defense. Now he’s hurt.

“We’re missing a lot of effectiveness at shooting the basketball. He’s been great. But that being said, those shots are going to be taken by somebody else. So those 17 to 18 shots, that usage is still going to be there,” Fernandez said.

“Then it’s your opportunity, and we can see somebody else stepping up. We’ve seen it so far in different ways, whether it is Dennis [Schroder] the other day, Cam Johnson, so it’s like, Jalen, all these guys, so excited to figure it out.”

In Thomas’ absence, more scoring burden will fall on the shoulders of both Johnson and Schroder, who finished with 29 against Phoenix.

Johnson returned Wednesday in Phoenix from a sprained right ankle suffered in the first quarter on Monday against the Warriors and finished with 11 points, eight rebounds and six assists.

“I stepped back and landed on Draymond [Green’s] foot,” Johnson said. “After the shot I was about ready to go run back on defense, and he was stepping forward as I was stepping back and I landed on his foot.”

With both Johnson and Thomas down, Schroder had scored 17 points in Monday’s fourth-quarter comeback. The Nets also will lean on Johnson, who made a return to Phoenix where he played before being part of the Kevin Durant deal.

“Honestly, I’m just happy to be able to have another opportunity to play basketball, no matter where it is,” said Johnson, who was averaging 19.7 points this month on white-hot 45.7 percent shooting from deep. The Nets will need more of that from him, and from Finney-Smith.

“I’m a little banged up,” Finney-Smith said. “I tweaked it last year. You do all the work to get your ankle strong, but then a basketball play happens and you tweak it again. But it’s part of playing basketball. That’s probably the thing you’re going to injure the most. We’ve got a bunch of guys banged up though, so it’s next-man-up.

“It’s tough. Sometimes [the staff] has got to save me from myself. … So if I can play, I’m going to try my best to be out there. And once I’m out there, I don’t want to hear nothing about no injury. I’m playing, so I don’t want to hear about it.”

Claxton admits he hurt his back over the summer, calling it a “long-term” issue that he will have to “manage.”

Clowney — in a walking boot and on crutches at shootaround — won’t be reevaluated for three weeks. The other backup center, Sharpe, hasn’t played this season but is expected to be activated “within the next week.” In their absence, the Nets had to start 6-foot-9, 205-pound Ziaire Williams, who scored 10 points, as a small-ball five.

Martin suffered a knee bruise Sunday in a G-League game and won’t be reevaluated for one to two weeks. The Nets offered no update on Bogdanovic, but sources say he will be reevaluated next month.