McInnes picked up and MCL injury in his side's loss to the Cowboys in the final with the seriousness of the injury still be confirmed though it can typically be a two to four week injury.

"Unfortunately Cameron has suffered a medial collateral injury to his left knee," club head of athletic performance Nathan Pickworth said.

"When we return home, he'll be undergoing scans to confirm the severity of the injury."

McInnes is a notable addition to an injury list that also includes Korbin Sims and Matt Dufty, with Sims suffering a fracture to his left arm making a try-saving tackle on Blake Ferguson in the Dragons semi-final victory over the Eels.

It's the same arm he broke in his first appearance for the Dragons last season, with the injury requiring surgery and keeping Sims out of action for eight weeks. His latest mishap likely to mean a similar amount of time on the sidelines.

It came after Dufty suffered a depressed fracture of his right cheekbone in his side's earlier pool clash with the Eels, though he will be able to travel with the team back to Sydney.

Tyrell Fuimaono was also unavailable for the final, leaving the Dragons with the bare minimum of 14 fit players for the tournament decider. They still went close to victory, drawing five points late before Hamiso Tabuai-Fidow iced the game late for the Cowboys.

It didn't leave coach Paul McGregor singing the tournament's praises in the immediate aftermath but he says there were some positives to take out of it.

"[McInnes] fell awkwardly on it and got a bit of a twist and at the moment they think it's a medial but we'll get an MRI once we get home and know a little bit more there," McGregor told NRL.com.

"Korbin's is a suspected broken arm and the other one is Dufty who's got a broken cheekbone. That's the downside of rugby league and contact sport, especially when you open the field up like we do in the Nines.

"At the moment I don't [like it] because I've got three injuries but I understand it's really good open game for the fans and the players love playing it. As a head coach you just hold your breath and cross your fingers.

"We've got a few injuries out of it so it's not ideal going into the start of the season but we'll get home, freshen up and get ready for our next trial against Newcastle."

It's always tough to glean anything out of success in the Nines format but McGregor said the tournament did highlight beneficial changes to the club's strength and conditioning set-up.

"It does re-enforce and demonstrate the correction we made in our preseason from previous years," McGregor said.

"I think we had a real honest look at ourselves and the preseason we had was very tough and this tournament's re-enforced it was the right one.

"Fourteen weeks is a long time for blokes to train without playing and through this and the scrambling we did and the desperation we showed at different times... you can't do that unless you're fit so they're fit.

"I was proud of the boys effort throughout the tournament, they really started to work hard for one another and develop that trust and belief you need when you get on the grass.

"We came over here with a want to be excited to play and be hard to beat and we certainly did those two things."

The loss in the final denied the Dragons what would have been a rare double crown after the club's NRLW side ran roughshod over the Broncos to claim the women's crown.

It also avoided what would've been a PR disaster for the NRL after the Dragons progressed to the semi-finals on the back of a refereeing howler that awarded young-gun Cody Ramsey the match-winner in his side's win over the Panthers in the quarter-final.

Trailing 17-13 with no time left on the clock, Ben Hunt lofted a kick to the corner with Ramsey pulling it down for what looked like his hat-trick of four pointers and the win.

With no video referee in operation, referee Ben Cummins relied on the reports of his touch and in-goal judges to award the try only for replays to show Ramsey hadn't gone close to getting it into the Panthers in-goal.

It was not up for review, except for the thousands and fans and viewers with the benefit of replays, who voiced their displeasure at an incident that sure to mar the entire tournament.

The Dragons ultimately ran with their piece of good fortune, getting one back on the Eels in the semi-final when Tim Lafai crossed with 30 seconds left after a break from Jackson Ford.

It saw them take an 8-6 lead with the Eels unable to pull off a Hail Mary play to sneak into the final.

It booked a final date North Queensland where their run fell short, with the Cowboys completing an undefeated run through the tournament to claim the trophy.