Paix and replacement rake Blake Mozer, who failed a category-two HIA, were both rubbed out in the second half of the 35-31 loss to North Queensland on Friday night.
The Broncos were already without injured star trio Reece Walsh, Ben Hunt and Adam Reynolds for the match.
The Paix ruling in the 45th minute of the clash had coach Michael Maguire perplexed ahead of next Saturday's clash at Wests Tigers.
The category one for Paix means he automatically misses the Tigers clash and also meant he was unable to come back on the field against the Cowboys.
There were fears Mozer, playing off the bench in his first NRL match since 2024, may have broken his jaw while trying to tackle Cowboys wrecking ball Jason Taumalolo.
"That is something we are going to have to review," Maguire said of the Paix ruling.
"Blakey was a cat-one and gets given a cat-two. Paixy ran off, passed the test and got a cat-one. I don't quite get that.
"I think Paixy will be fine for next week. He was ready to run back out. That is a call made externally so I will go through the right channels with the doctors and review that one. Talking to Paixy, he can't believe it himself.
"Then on the flip side, you have got Mozer with a jaw potentially broken."
Doctors were assessing Mozer in the dressing room after the match.
"It a real shame," Maguire said.
"He has worked really hard and I thought he was going really good out there. We were all excited for him."
With other roster hookers Hunt and Billy Walters injured, the Broncos may turn to 20-year-old Cameron Bukowski, a highly rated No.9 who has a development contract.
"I've had a good conversation with a few of the boys and we think he is ready," Maguire said.
"Cam has been battling away, fighting and working hard in the background. An opportunity might be around the corner."
The Broncos had lock and stand-in captain Pat Carrigan put on report and sin-binned for what was ruled a shoulder to the head of Cowboys centre Tom Chester.
"It is tough. I didn't get to see the replay but I honestly felt like he hit me square on in the chest," Carrigan said.
His coach agreed.
"It was chest. That's how I saw it. It is interesting, because I thought it was a really good chest tackle," Maguire said.
The coach added that the side "really dug in for each other" despite not getting the result they wanted amid "a fair bit of carnage".
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