Cowboys back-rower Gavin Cooper said the inability to convert patches of good play into victories remains the biggest problem facing his side.

Last week North Queensland were down and out after Wests Tigers raced in three tries inside the first 20 minutes.

That came after blowing a 14-4 against the Sharks and a week earlier conceding three tries in the final 10 minutes en route to a 12-point loss against South Sydney.

Another down period in Thursday night's clash with the Broncos at 1300Smiles Stadium will make an already difficult job even tougher.

"It's about showing each other, [and] proving to each other, that we believe in what we're doing, believe in each other," Cooper said.

"You've seen patches where it all looks good but then when things go bad, that's when we turn really bad. If we can eliminate that from our games, we'll be in most games.

Cowboys v Broncos - Round 21

"We've got to stop those lapses somehow and there's no better test than the Broncos at home in the derby, it doesn’t matter how both teams are going, both teams will show up ready to play."

Cooper, who is yet to give up on the finals despite the Cowboys being four points out of the eight with five matches remaining, said the players need to rediscover the trust that played such a large role in the club's success over the past five years.

"We've just got to trust in what we're doing. I've been a part of this before. I've also been a part of some winning runs where things become second nature," he said.

"Losing's become second nature to us at the moment because we get in front and we put the brakes on because we don't really know how to put a game away.

"If you can't get up for a Broncos game here at home, you're going to really struggle. There's no better time than this week to turn one on."

Young Cowboys halfback and Tully Tigers junior Jake Clifford said the Cowboys-Broncos rivalry was part of his life well before he signed with the NRL club.

"There were a few Tully trips coming down and watching the Broncos versus the Cowboys and I loved every minute of it as a fan. I don’t think there is a better rivalry, it's always very close," he said.