Dyldam Parramatta Eels Head Coach Brad Arthur says the message from Saturday night's loss to the Sydney Roosters is simple: defence is key.

"That brought us back to earth pretty quick," Arthur said of the 56-4 loss to the reigning premiers.

"[They scored] fifty points."

"We need to be better with our defence, that’s all there is to it: you can’t give a good team like that back to back sets and good field position."

Earlier, Roosters Head Coach Trent Robinson was adamant that Eels lock Darcy Lussick should have been sent off rather than put on report for a hit on Roosters prop Jared Waerea-Hargreaves, but Arthur was more reserved.

"I’ll have to watch the replay," Arthur said.

"I’ll leave that up to the refs."

Co-Captain Jarryd Hayne pointed to the halftime break as the moment when the match ran away from the Blue and Gold.

"They definitely could have put more points on us that first half," Hayne said.

"But we dug deep and turned them away."

"Then they’ve just come out in that second half and dominated and we couldn’t go with them."

"We could have and it up to 14-10 at halftime but it wasn’t to be."

"The disappointing thing is knowing that we stuck in there that first half, and then the start of that second half, they just got that roll on and blew us away."