'Total opposite': 'Frustrated' Anthony Seibold surprised by Manly drop off in loss to Eels

Manly coach Anthony Seibold said his side's 20-point thumping to the Eels caught him by surprise, especially after the club's performance last week.

Manly's 24-6 win over the Cowboys last round was a standout performance in what has been an inconsistent season so far.

Both sides were missing key players with halfback Daly Cherry-Evans out for Manly, while the Eels were without No.7 Mitchell Moses and Zac Lomax.

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Manly led 4-0 early and then levelled the match at 10-10 before halftime, yet the Eels had more options on the edge and up the middle as the Sea Eagles defence struggled.

Parramatta made five line-breaks on Friday night, with four of those coming in the first half.

"So good last week against the Cowboys away from home, gritty and really connected. Then tonight we looked the total opposite," Seibold said.

"In saying that I have to give credit to Parramatta, they played really well and did the hard things for very long periods.

"But it's frustrating because as I said, we were so good last week and we felt as though we had turned a corner the last couple of weeks."

Seibold attributed his side's scattered defensive line in the first half to halfback Jake Arthur's HIA, which forced a couple of players out of position.

"I think, Jake Arthur came off early so we had a hooker defending at three man and Corey Waddell went into edge back rower today," Seibold added.

"There was probably a little lack of cohesion for a few of them. The disappointing thing it doesn't matter, they are inside shoulder tackles and that's the golden rule defensively.

"They poked some holes through us there in the first half, as I said, Parramatta were too good for us tonight."

Seibold was also asked about Jake Trbojevic's return to the team after suffering from concussion.

The Manly coach confirmed the key forward will take all the time he needs.

"I'm not sure (he will be back), we need to do the right thing by Jake. He needs to see the independent doctor from what I understand,"

"But we will look after Jake, we need to look after him but he is feeling a lot better. He is back exercising."