Roosters coach Trent Robinson says he won't be concentrating on just field goal practice with his squad next week but zeroing in far better defence, which he labelled "a disgrace" after the Cowboys' upset 15-12 win at Gosford on Sunday.

Cooper Cronk missed two field goals and Luke Keary one in a distinctly un-Roosters-like way of breaking a locked-up scoreboard.

"It was an opportunity to win the game there on three occasions," Robinson said.

"I was very disappointed in our defence on those two tries… really poor," he added in reference to Jake Clifford changing direction close to the line and finding a gaping hole, while John Asiata at the other end merely pushed through defenders to plant the ball on the white line.

"That's just unacceptable…. It wasn't a game where we had any continuity to get more points. They defended well when we asked them questions.

"At 12-6 we were in control there… but to let that try in there – and well done to John – but that was a disgrace."

That is now five losses in the past seven games for the Roosters.

"That's indicative of how we're feeling…. I thought we were good against Melbourne [a round 15 two-point loss] and the Tigers [a 24-16 round 16 win] but we were just waiting for it to happen again today.

"We were trying to get to the good parts before doing the hard work."

Robinson added he had no regrets about resting NSW Origin stars James Tedesco and Boyd Cordner.

"That result is not based on not having those two there," he said.

"We had enough guys out there to either finish the job off or work hard enough so we weren't in that position."

Robinson said the effort was high but the form was low. "The balance is not there yet," he added.

What also seemed off-kilter to Robinson was the referees placing Jared Waerea-Hargreaves on report in the 13th minute for leading with his head in a tackle on Josh McGuire. Play carried on before the officials called the prop out.

"I don't know where that came from… it was a post-report… who reports that?" Robinson said.

"This is brand new – again."

The Roosters have the Knights, Bulldogs and Titans over the next three rounds to try to right the ship – two of those three at home at the SCG.