Matthew Primus' embattled side blew a 40-point third quarter lead to hand Gold Coast its first ever victory at AAMI Stadium in round five, and was thrashed by North Melbourne at Etihad Stadium on Saturday.
But Sewell said the Hawks will need to be ready for Port at its best this week.
"You can't afford to take any game too lightly, regardless of the opposition, and we're well aware of that," Sewell said after Hawks training on Monday.
"I think in our planning for the game we need to remove the element of worrying about what sort of mood the opposition are in.
"When they're up and about and going well, they can beat anyone on any given day, so we need to be well prepared."
Livewire forward Cyril Rioli, who hurt his hamstring against Geelong on Easter Tuesday, jogged laps as his teammates trained and appeared to be moving freely.
But Sewell said the club won't gamble on the fitness of such a crucial player.
"He did a little bit today, but he's the sort of guy we certainly won't be risking," Sewell said.
"Fingers crossed he can do a little bit more later in the week, and whether he comes up or not we can only hope."
