Parramatta face a nervous wait on scans for star Corey Norman after the halfback suffered a suspected knee injury in the 48-10 loss to the Sydney Roosters.
Norman limped off after getting caught awkwardly in a tackle from behind by Roosters prop Jared Waerea-Hargreaves in the second half on Sunday.
Norman's injury compounded a lacklustre Eels performance and they were barely in the contest against a rampant Roosters outfit at ANZ Stadium.
Eels coach Brad Arthur admitted he could be without his chief playmaker for up to four weeks.
"Obviously they'll need to send him for scans but i think I've been told a grade two medial... maybe four weeks, but there was a bigger blow today and it wasn't Corey Norman," he said.
The loss snapped the Eels' three-game winning streak.
Wing pair Daniel Tupou and Blake Ferguson combined for five of the Roosters' eight tries, while Latrell Mitchell bounced back from his reserve grade dumping to score a try and set up another.
Eight days out from the naming of the NSW team for the State of Origin opener, Roosters halfback Mitchell Pearce had two try assists and contributed to two more.
The win was the Roosters' second in their past six outings and lifts them back in to the top four - just two points behind leaders Melbourne.
The Roosters led 28-4 at halftime when Mitchell produced a brilliant offload in the midfield, igniting a 65-metre attack that ended in Tupou scoring in the corner.
Eels centre Michael Jennings pegged one back, but Ferguson then crossed twice to complete a hat-trick and Joseph Manu also went over.
Roosters coach Trent Robinson conceded being concerned whether his team would go on with the job in the second half, after a weekend where teams struggled to hold on to big leads.
"We've seen some funny results this weekend. Some teams haven't been ready to play 80 minutes," he said.
"After halftime there was a period there where that was critical, the first 10-15 minutes after halftime when you're 28-4 up was going to decide how that looked."
The signs were ominous from the outset for the Eels fans among the crowd of 10,467, with Mitchell palming off Kirisome Auva'a for opening points to start a dominant period of six straight Roosters sets.
In the space of 10 minutes, the hosts were out to a 14-0 and were racing the clock after Michael Gordon kicked a penalty goal and Jake Friend sliced over from close range.
Eels winger Clint Gutherson stemmed the tide when he finished off a 60-metre movement, but more ill-discipline condemned the visitors to their worst first half of the season.
Gordon nailed another penalty goal before Tupou raced 45 metres after latching onto Kenny Edwards' errant pass, and Ferguson went over just before the break.