"It's always tough playing Manly, particularly at Fortress Brookvale - and they are a very good team," he said.
"Beating Manly means you have to go with them, they're very good across the park, particularly out wide, so defensively we've really got to be on our game."
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The Sea Eagles will likely be bolstered by last week's return of fullback Brett Stewart, who will play opposite Jake Mullaney in Blue and Gold.
"Brett Stewart is a quality player; he's been in Origin the last couple of years and has a phenomenal strike rate scoring tries at Brookvale Oval," Parish said.
"He pushes up the middle very well but is also very hard to handle on their right side especially with his brother Glenn and Jamie Lyon."
Parish admits the Eels will have to be strong across the entire park to beat the Sea Eagles.
"Their outside backs are very strong, on their right side Cherry-Evans, Glenn Stewart, Jamie Lyon and Dave Williams; on their left, Keiran Foran, Justin Horo, Steve Matai and Jorge Taufua."
"So with Brett Stewart at the back to fnish it off, they're very strong."
Watch Matt's full video previewing tonight's clash with the Sea Eagles above.