"They're a tough team Manly," he said. "They're going to fight their way back up and they're always going to be a competitive team. They've got heaps of great calibre players.
"They'll fight to the end because they've always been that kind of team, with how they go in finals."
Manly have won three of their last five in the NRL and they beat the Warriors 22-12 at the end of July in Auckland last season.
The Roosters comfortably beat the Warriors 24-0 last weekend and head coach Andrew McFadden knows they have to improve if they stand any chance of winning this weekend.
"They're still chock-full of talent and they've got a lot of quality," he said. "Their halves are first class and we're going to have to play a lot better this weekend to win.
"I'm not putting too much attention with what's happening on their side. Through the week we focus on our own performance. I don't actually know their situation at the moment and we're more worried about ourselves."
Manly should also be wary of the reaction they could face from the Warriors as Thompson said they were hurting from their humbling in Sydney.
He said: "We're obviously not feeling too good with the loss. It's just one of those things that we've got to put behind us and get improvements out of it to go into this week to prepare ourselves. It is a little kick up the butt and it makes us realise what we have to do."