The State of Origin forward went into self-isolation after he invited a guest to his room overnight, meaning he was unable to train with the team on Friday and is out of Melbourne’s Sunshine Coast Stadium match on Saturday night.

From midnight, Melbourne players and staff were free of strict quarantine “bubble” conditions, given it had been two weeks since they’d played a team from NSW, but the investigation is looking into when the visitor arrived in the hub.

The Storm briefed the NRL Integrity Unit and Queensland Government early on Friday.

Chief executive Dave Donaghy wouldn’t reveal the player as Welch at the time of the press conference but said the player was “incredibly upset” while the club was also very disappointed in his actions.

“There was a possible breach late last night with an unregistered guest to the bubble’s premises,” Donaghy said on Friday.

“We disclosed the matter to the NRL early this morning … we are seeking some further details.”

Donaghy said that Welch had to be stood down while the investigation continued into the timing of the incident

“That just comes from being in isolation,” he said.

“The reality is there’s a potential or possible breach and for us that means there’s appropriate testing that will be undertaken and that will be resolved really shortly.

“That’s to ensure the health and well-being of the wider group.”

He said he spoke to Queensland’s Chief Health Officer Dr Jeannette Young on Friday who assured him there was very low risk of COVID-19 transmission among the community.

“We’re confident the test won’t come back anything other than negative but it has to go through a process,” Donaghy said.

Welch was due to return to the Storm line-up after a one-match suspension for a crusher tackle.

-AAP