Sydney Roosters coach Trent Robinson is concerned his side’s ill-discipline could cost them in the NRL finals series.

The Roosters moved to the top of the NRL ladder with a 42-6 win over Penrith on Friday but once again were on the wrong side of the penalty count at Centrebet Stadium.

Robinson’s side have won the penalty count on just three occasions this season and the 35-year-old said he would be speaking to referees boss Daniel Anderson next week to find out how his team can improve.

“That was poor again tonight. I feel I need to talk to the referees about some of those penalties,” Robinson said.

“I feel like they’re really critical of us in that area but I’m not saying that we don’t need to improve either.

“I need to make sure I’m working with them as well and getting that (message) back to our players.

“We’re trying to work on it, I think you can see we’re working hard with the refs there but (what happened tonight) is still not good enough.”

Although he was frustrated by his side’s being on the wrong side of calls from the referees, Robinson refused to blame the whistleblowers

But he does believe his team were now being penalised on reputation by officials and said it is a long-held view that his side deliberately infringe when defending.

“It’s significant penalty counts for a decade through many different coaches but I don’t think (that) dictates what happened tonight,” he said.

“You can’t say that they went back a decade and decided to penalise us tonight but there’s been significant penalty counts for a long period of time.

“But so what, it’s up to us to fix it and we need to do something about it and we haven’t done that this year yet.”