The Panthers trio, along with Newcastle's Shaun Kenny-Dowall and Danny Levi, were all given contrary conduct charges on Sunday for the late brawl in Penrith's 20-12 loss.

However, the lesser nature of the charge - as opposed to striking, which was handed out for punches thrown in a fight between Manly and Melbourne earlier this year - only carries a $1500 monetary fine which can be reduced with an early guilty plea.

Of the five, Blake was the only player charged not to be sin-binned, while Kikau, May and Kenny-Dowall were each spotted throwing punches in the melee.

The news will come as a relief for the Panthers, who now appear likely to finish outside the NRL's top four after leading the competition at the half-way mark.

Saturday's loss to Newcastle dropped them to fifth and equal on wins with fourth-placed St George Illawarra and sixth-placed Cronulla.

However, the Panthers have a difficult run home on the road that includes the Warriors in Auckland and Melbourne at AAMI Park.

The loss was their first in four weeks but Penrith have been far from convincing in a two-month period that claimed the head of coach Anthony Griffin.

Their past three wins were all come-from-behind efforts against teams well outside the top-eight and with little to play for, while Penrith have also been beaten heavily by the Sydney Roosters, Brisbane and Cronulla in that period.

The Panthers are without five-eighth James Maloney for the run to the finals, while they coughed up 15 errors against the Knights.

Crucially - and while it is early days - their trajectory does not appear to have changed in the two weeks under interim coach Cameron Ciraldo, who has controlled their attack all season.

"If they play this kind of football they are out of the finals series immediately. They were terrible," rugby league legend Peter Sterling said on Nine's Sunday Footy Show.

"They weren't playing that well when Anthony got the bullet. There were some signs there but there has been no turnaround since."

Sterling said the late brawl with the Knights was an indication of the team's frustrations.

"Out of this there are a couple of players who lose their way for Penrith. It's a bad sign for as to where they are mentally for this stage of the season," Sterling said.

"Their defence has been awful for weeks and weeks, and yesterday their ball control was non-existent. They played like strangers."

Australian Associated Press