Klemmer was linked in a shock move to the Parramatta Eels just hours before the NRL's transfer window closed on Monday.
While he came out suggesting he never considered exiting the Hunter, it was just 24 hours later that he was stood down from the team, with the Knights releasing a statement shortly afterwards stating the veteran prop had been issued with a show cause notice for an on-field disciplinary matter.
"The Newcastle Knights have issued David Klemmer with a show cause notice relating to on-field disciplinary matters in last Sunday’s match against the Canterbury-Bankstown Bulldogs," the club wrote in a short statement.
"No further correspondence will be entered into until the show cause hearing process has been completed."
Reports later suggested that it was for refusing to be substituted out of the final minutes of Sunday's loss to the Canterbury Bulldogs, and verbally abusing a trainer.
The Daily Telegraph are now reporting that Klemmer is no guarantee to stay at the club, with the Knights reportedly considering ripping up his contract.
It's understood that talks will continue in the coming days along with the show cause notice hearing which Klemmer has been stood down over for this weekend.
Klemmer has previously been linked with an exit from the Knights following the club's call to re-sign twins Jacob and Daniel Saifiti last year, reportedly having no interest in playing from the interchange bench.
He has got back to his best in the starting side this season though, cementing his position as a starting prop while the Saifiti's have struggled to hit their best form.
Snubbed from the Origin arena, Klemmer has been the shining light in a difficult season for Adam O'Brien's Knights, but is off-contract at the end of next year.
It's reported that a group of players have not taken the news over Klemmer's stand down and treatment well, planning to confront the club over the situation.
Support of his teammates could yet see Klemmer remain at the Knights after he told The Newcastle Herald that he was "committed" to the Knights amid speculation of his exit on Monday.
The Knights are out of the finals race, sitting 14th on the table with just five wins from 19 games, and will play the Wests Tigers, Brisbane Broncos, Canberra Raiders, Gold Coast Titans and Cronulla Sharks over the final five weeks of the season.