The Parramatta Eels are facing a big selection headache for their NRL preliminary final trip to Townsville, with Tom Opacic in considerable doubt.

The centre went down with a hamstring injury during Friday evening's blowout 40 points to 4 win over the Canberra Raiders in the semi-finals, being taken from the field and unable to finish the game.

He was eventually seen with an ice pack on his leg as he watched on from the bench, and even a minor strain would still likely rule him out for at least a week, with the centre, who has played 18 games this year, would then be forced to race the clock ahead of the grand final.

The Daily Telegraph's David Riccio told Triple M Radio on Saturday morning that there was some optimism around the severity of the injury, but that he would be in doubt.

“I spoke with the Parramatta club this morning,” Riccio said on Triple M.

“There is some optimism in relation to the severity of the hamstring issue. I think you’d have to place Opacic in serious doubt to play.

We know hamstring injuries are problematic and going into a must-win prelim, it’s probably too big a risk to take. But, if they were to advance, I wouldn’t rule out Opacic going forward."

Maybe of more intrigue is the idea that the Eels could use Marata Niukore to replace Opacic in the centres.

The utility forward, who has spent time in the centres over the last 24 months, is due to depart the club for the New Zealand Warriors next year, but has been used as a starting lock ahead of Ryan Matterson in recent weeks.

“The option I’m picking up on is Marata Niukore at this stage shifting into the centre spot, with Waqa Blake staying on the wing. A little bit of water still to flow but optimism that beyond the prelim, Opacic may be OK," Riccio said.

Niukore's value starting at lock has allowed Ryan Matterson to turn into something of a wrecking ball coming off the bench, and so him moving to the centres is on the surface an intriguing decision.

That is even more so the case when Bailey Simonsson, who joined the club from the Canberra Raiders ahead of the 2022 campaign, is amongst the reserves but hasn't been utilised in recent times.

Simonsson playing would also allow Waqa Blake to shift to his preferred position in the centres.

Should Niukore move to the centres, it's tipped Matterson would be forced to start, although Nathan Brown could still fill the void, with Bryce Cartwright the other option to come into the side should Matterson start and the vacant place be on the bench.

Parramatta will name their team for the trip to Townsville at 4pm (AEST) on Tuesday.