The 24-year-old was a standout for the Dragons at the NRL Nines and also had quality touches in the Indigenous All-Stars clash on Saturday before succumbing to the knee injury.

There were initial fears he could be looking at the 6-12 weeks skipper Cam McInnes is facing with the same injury but Dragons head of performance Nathan Pickworth said scans have confirmed just a grade one tear.

"Unfortunately Josh has suffered a grade one medial [strain]," Pickworth said.

"He'd had a really good preseason, played a good nines tournament and was playing well in [the All-Stars] game so it's really unfortunate that he's suffered an injury at this time of year.

"The fortunate news is we estimate the return to play is two to four weeks so Josh will be working really hard to give himself every chance for round one."

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McInnes has made clear his intention to return ahead of schedule after suffering a grade three MCL sprain at the Nines, with Pickworth saying he's tracking well.

"Cam's coming along well he's started to do some strength training in the brace," Pickworth said.

"The ligament's starting to tighten up and we've been able to open his brace up a little bit further which gives us an opportunity to do a bit more training with him.

"Hopefully he'll be out of the brace early next week and we can start getting him running not long after that."

In other positive news, young-gun Jayden Sullivan has avoided the need for surgery despite suffering a high-grade ankle sprain at training in the lead-up to last week's Knights trial.

"It was training Wednesday night he just changed direction and got his ankle caught under tackle," Pickworth said.

"It all happened quite quickly and he got his ankle caught in an awkward position.

"Scans have revealed he's had a grade three lateral ligament strain. Fortunately he doesn't need surgery, he'll just need a period of rest and recovery.

"The good thing about these injuries is they can recover quite quickly. He'll be aiming somewhere between round one and round three to get back on the park."