The West Tigers co-captain was involved in a social distancing incident with 7NEWS Sydney reporter Michelle Bishop, which was immediately brought to the attention of the NRL as per guidelines.
Under the guidelines, there is to be no contact with anyone outside of the 'bubble' aside from people in their homes, which have been pre-approved by the NRL.
No one from outside the bubble, including media and other club staff, are allowed inside 'clean' zones at games and training sessions.
Nine News has reported a kiss on the cheek was what resulted in Marshall's separation from the team.
Marshall will remain home tomorrow while Bishop undergoes a Covid-19 test.
Assuming a negative result is returned, no further action will be required by Marshall or Wests Tigers.
Bishop has since apologised for the hiccup on Twitter, confirming she was on her way to a testing centre.
"Just goes to show you, we can all get caught up in life and forget what kind of world we are living in at the moment," Bishop wrote.
"Off to be tested #innocent #awkward #apologies."
It's the second scare for an NRL club since the season restarted two weeks ago.
Last Thursday, Canterbury great Terry Lamb was sent for a test after he greeted a number of Bulldogs players at training.
Meanwhile, Marshall admits he was shocked when told of his dumping from the Wests Tigers NRL side yesterday.
The NZ skipper is one of several changes made by coach Michael Maguire, after the club's surprise loss to the Gold Coast Titans on Sunday.
Marshall was said by the Sydney Morning Herald to have "cut a dejected figure" on being given the news, a potential blow to moral within the Kiwi camp as well.
"I was a little bit shocked and disappointed that I got dropped," he told NRL 360.
"Any player would be in that position. If you're competitive and you want to be part of the team, of course you are going to be disappointed.
"What the coach has done has really put everyone on notice that we're looking for consistency, so you can't go up one week and down the next."
Marshall has been replaced by Josh Reynolds, who will partner Luke Brooks against the Cronulla Sharks this weekend.
