The Roosters paid for their ill-discipline against the Panthers on Saturday night but their coach says the referees were also below par.

Robinson takes aim at refs after loss

Frustrated Roosters coach Trent Robinson has taken aim at the performance of the referees in his side's 19-18 loss to Penrith on Saturday night for allowing the game to be slowed down by stoppages.

While stressing he was disappointed in his own side's efforts and praising a Panthers side he said fully deserved its win, he also blasted the way the game was handled and a crucial no-try call against French prop Remi Casty.

"I thought the referees were off again tonight, I didn't think they were up to performance either – this is semi finals," Robinson said.

"They were missing the opportunity to keep this game going, we had that many stoppages in the game – it wasn't semi finals. They needed to lift their game there, those two [Jared Maxwell and Henry Perenara] weren't ready for that tonight."

He blasted their failure to stop the game when Roosters playmaker James Maloney went down with an ankle injury while halting play when Panthers hooker James Segeyaro was troubled by cramp.

"You don't stop the game for cramps. That's what semi finals are – semi finals are 'keep playing footy', you can't stop for a cramp, that's what our game's about. Play on. We want attrition in our game, they talk about attrition and reducing the interchange and all that – keep the game going," he said.

A possible try to Casty in the 50th minute – which came after the referees had called held but before Casty's ball-carrying arm had touched the ground – earned Penrith a desperately-needed penalty, halting the Roosters’ momentum, and denied them what could well have been a match-clinching try.

With Penrith trailing 12-4 at that point, the Panthers got another penalty straight away and scored at the end of that set to close the gap to 12-10.

"That was a try, you can't miss a try in semi finals. You go upstairs. They went upstairs for everything, you go upstairs for that try. Penrith won the game and won it fair and square but that wasn't good enough," Robinson fumed.

"Penrith won the game but that needs to improve, that wasn't good enough from [the referees] tonight – too many stoppages, too many poor calls. Henry was talking a lot about us, never mentioned Penrith. That was poor from Henry. Penrith needs to be the focus but that wasn't good enough."