Parramatta Eels coach Brad Arthur has defended a call to select his son over the last fortnight, suggesting he picked his best 17 and labelling the criticism from fans as "unfair."

A backline crisis at the Eels, with multiple injuries piling on top of one another, forced coach Arthur to move star five-eighth Dylan Brown to the centres for a fortnight, selecting his son Jakob to play at five-eight, building a halves combination with Mitchell Moses.

After a 39 points to 2 pasting of the Newcastle Knights in the first week with the combination, it all fell apart in a difficult trip to Darwin last week where the Eels were shocked by the North Queensland Cowboys 35 points to 4.

Arthur has now been able to welcome back Tom Opacic into the side for this week's critical clash against undefeated defending premiers the Penrith Panthers in what is likely to be a ferocious Western Sydney derby clash.

It has allowed Brown to move back to five-eight, and Arthur to drop out of the side, with the coach telling reporters on Thursday that he was simply selecting his best 17 over the last fortnight.

"I did what every coach would do: pick your best 17 and then I put them in positions," Arthur said on Thursday.

"It worked for us the week before. It didn't work this week and it certainly wasn't his fault.

"I felt like we didn't compete at every contest and we didn't have the same attitude and effort as we had the week before.

"If we played the same way as the week before it's a different story."

TOWNSVILLE, AUSTRALIA - MAY 18: Eels coach Brad Arthur speaks at the post match media conference at the end of the round 10 NRL match between the North Queensland Cowboys and the Parramatta Eels at 1300SMILES Stadium on May 18, 2019 in Townsville, Australia. (Photo by Ian Hitchcock/Getty Images)

Arthur said the criticism of his son is unfair.

"Look, it's unfair. But it's what it is. People are entitled to their opinion. I suppose it's always harder when it's your own flesh and blood," Arthur said.

"But he (Jake) is fine. He doesn't do social media so he didn't know a hell of a lot what was going on until he got some nice messages from people just checking to see if he was okay.

"He was asking on Monday night what all the commotion was around and I sort of told him and, yeah, just moved on.

"The pleasing thing for us is we get a few troops back and then he'll go back and play (NSW) Cup. He enjoys playing there."

It comes after another star playing under his father, New South Wales and Penrith halfback Nathan Cleary, fed some advice to Arthur during the week about dealing with criticism from fans.

The Eels take on Penrith away from home on Friday evening.