An injection of backbone into a side that wilted from 18-0 up to slump to a costly home defeat by the Knights will appear extremely welcome.
The Knights reverse has left the Warriors' playoff hopes dangling by an increasingly frayed thread. A win against the Sea Eagles would repair some of the damage, however Manly have long been a bogey side.
A 26-24 win at Brookvale in 2009 was the Warriors' lone success in the last nine clashes between the clubs.
Playing at a neutral venue should increase the Warriors' prospects, however the loss of Mannering still looms large.
Manu Vatuvei returns from a hamstring strain to take the captaincy for the first time, while Ben Henry shifts into the back row and Lewis Brown to centre in the reshuffle.
A five-man bench includes both Lousi brothers Sam and Sione as well as Jacob Lillyman and Ikahihifo. Pita Godinet appears the likely 18th man.
The Perth trip will be a smash and grab raid, with the Warriors flying in - a rare trip in business class to minimise the travel effects - and then hopping on the first available flight out to begin recovery at home ahead of the following Saturday's match against the Sharks at Mt Smart Stadium.
"Our research over the years says it's best if we get in as late as we can and get out as early as we can," McClennan said. "We've got our backs against the wall here. We've got to go over there and perform well against Manly - a side that have bullied us over the years.
"We'll get good support in Perth. There are a lot of Kiwis there and it will be nice to play in front of them. We're not dead, but we need to break a bit of a hoodoo against Manly."
SEA EAGLES
Perth, 9.30pm Saturday
Dean Whare
Jorge Taufua
Jamie Lyon
Steve Matai
David Williams
Kieran Foran
Daly Cherry-Evans
Jason King
Matt Ballin
Brett Kite
A Watmough
Tony Williams
Glenn Stewart
Sea Eagles: Jamie Buhrer, Joe Galuvao, Darcy Lussick, George Rose, Vic Mauro, Daniel Harrison.
WARRIORS
Kevin Locke
Bill Tupou
Lewis Brown
Konrad Hurrell
Manu Vatuvei (c)
James Maloney
Shaun Johnson
Russell Packer
Nathan Friend
Ben Matulino
Feleti Mateo
Ben Henry
Elijah Taylor
Warriors: Sam Lousi, Sione Lousi, Jacob Lillyman, Sebastine Ikahihifo, Pita Godinet.