NRL boss Dave Smith says it is riduculous for anyone to suggest there is a conspiracy against the North Queensland Cowboys.

It has been a tough week for the Cowboys, with back-rower Tariq Sims copping a lenghty five-week ban for a late shoulder charge on Broncos full-back Justin Hodges during last week's elimination final.

The club was later fined $10,000 after coach Paul Green's said the reason the Cowboys had not contested Sims' charge was because they had no faith in the judicial process.

Speaking in Rockhampton on Wednesday, Simth said North Queensland fans could not keep thinking the club is treated unfairly.

I think that's a ridiculous notion," Smith said.

"One of the best games I've watched this season was at the Cowboys stadium.

"I think they're going great guns. I think they're having a great season and I'm really looking forward to watching on Friday night back in Sydney.

"Its a ridiculous notion this conspiracy theory."

The Cowboys will face the Sydney Roosters in a semi-final at the Sydney Football Stadium on Friday.