Newcastle Knights winger Nathan Ross is unlikely to line up for this Sunday's clash with the Panthers after public comments he made in the media over seeking a contract upgrade at the club.

The 28-year-old signed an extension last season through to the end of 2018 but was quoted in the local Newcastle paper on Thursday morning saying he was seeking a pay rise based on his strong performances to start the season.

Ross trained with Newcastle's Intrust Super Premiership side on Thursday.

Knights coach Nathan Brown admitted he was disappointed with Ross's actions and hinted the Knights' leading try-scorer this season could be demoted for the clash with Penrith on Sunday afternoon.

"We'll keep what we're going to do with [Ross's selection] in-house and we'll move forward," Brown said.

"Firstly I think we're probably in a rare situation at the moment, for all clubs the cap is going to rise a rather large portion, whether it's 20 or 25 per cent, roughly in that vicinity.

"We haven't seen this happen probably since the Super League days.

"Rightly so, players that are on contract and probably not earning what their current market value is would probably like to get a piece of the pie.

"We're seeing this at every club, it's not only the Rossy situation.

"But there are certainly ways you handle it and I'd suggest Rossy didn't handle it in the correct manner.

"But we'll move forward and get over it."

Utility back Brendan Elliot is set to replace the City Origin representative on the wing after training alongside Peter Mata'utia on the left edge on Thursday, while Mitch Barnett is expected to return after missing the past fortnight with an ankle injury.

It was a surprise boost for the 23-year-old who was originally expected to miss up to eight weeks of the season after leaving the field in the Knights' loss to the Cowboys in Round 8.

"I went and saw a surgeon and he said he wouldn't operate on it which was good and we got a couple of other opinions and they all said 'you'll be right'," Barnett said.

"I was constantly getting physio and treatment on it coming in on the weekend and being aggressive with it through a bit of pain.

"I got back out there running, got it warm and it felt really good, everything lined up for me and luck went my way."