Parramatta fear they've seen the last of Maika Sivo this year after the powerful winger left Cbus Super Stadium on crutches after suffering a knee injury.
Sivo is due for scans on Sunday which the Eels expect will confirm medial ligament damage in his right knee, after it was twisted in a tackle in Saturday's 32-16 win over North Queensland.
Sivo would be expected to be out for at least the last two weeks of the regular season, but depending on the severity he could be in a battle to come back in the finals.
His injury could open the door for a Blake Ferguson return, with the off-contract veteran is fit again.
"I think they said MCL," Arthur said of Sivo's injury.
"He will need scans in the morning. We are pushing it to get him back this year.
"Fergo is back this week, Fergo will come back onto the wing and Haze (Dunster) will probably have to swap over to the other side of the field."
Sivo may not be the only issue for the Eels.
Nathan Brown is facing a potential one-match ban after being put on report for a crusher tackle on Reuben Cotter in the first half.
Hooker Joey Lussick was also put on report for dangerous contact, and while it's likely he could escape with a fine any ban would be a big hit to their dummy-half stocks.
"I didn't think at the time there was much in them," Arthur said.
"We'd have to play Will Smith there (at hooker if Lussick is suspended), but I didn't think there was much in it."
Parramatta have the hardest run home of any team with Melbourne and Penrith in the final fortnight, but Saturday's win still kept their faint top-four hopes alive.
Beyond that though, the Eels will be hoping the victory can swing their confidence no matter how scrappy it was, after a horror month where they lost four straight.
"We had one job tonight and that was to win a game of footy," Arthur said.
"It's very hard when you have lost four in a row and the form we've been in to execute a plan and get it right straight away.
"We tried hard. The two things we wanted was a bit more energy and line speed in defence. We got that."
Australian Associated Press