Expecting a fierce forward-orientated battle, the Cowboys made a key tactical change before travelling south, with youngster Michael Morgan replaced by veteran Grant Rovelli.

The Rabbitohs had concerns of their own, with coach John Lang busily trying to avoid a flash flood that had forced staff to immediately evacuate their Redfern Oval training complex because of an electrical scare.

"It is a different challenge for us, playing in these sorts of conditions," Cowboys coach Neil Henry said from a rain-soaked Sydney on Sunday night.

"We need to be strong in the pack, because it is a real strength of Souths.

"They have some big mobile men and Issac Luke feeds off that momentum from dummy half. We really need to muscle up and then control our possession.

"We were very disappointed last week, so this really is a big game for us in the context of our season."

Morgan was heavily targeted by Manly last week and - fearing an encore from wide-running Rabbitohs Dave Taylor and Sam Burgess - Henry has decided to promote Rovelli as Johnathan Thurston's sidekick on Monday night.

"Michael has been carrying a bit of a shoulder problem," Henry said.

"He had to make 40-odd tackles last week and he has pulled up a bit sore.

"Souths put a lot of traffic down those edges and we need all hands on deck there.

"Grant has been dominant for Mackay the past few weeks. He set up a few tries and organised their attack, so he deserved the opportunity to come back in."

Monday nights have become a favourites' graveyard, with eight of the last outsiders in betting causing boilovers.

Lang is hoping the Bunnies, $1.42 hopes with Tattsbett, can buck the trend at ANZ on Monday night.

"It all comes down to how you play on the night, that's the bottom line," Lang said.

"North Queensland are a lot better side than their position on the ladder indicates, particularly with Thurston, Matty Bowen and (Aaron) Payne back. If they can keep those three on the field I think they'll have better days ahead."

Lang was delighted with the more consistent performance in last weekend's win over Penrith.

He said the eight-day turnaround had only helped some of his players overcome injury.

Michael Crocker, however, will not make a shock return.