Up to 150 guests had been invited to Pearce's wedding to fiance Kristin Scott, before they were notified last week that the wedding would not take place on the planned date.
The scandal has threatened to overshadow the Knights' preparations for the 2021 NRL season, and the club's GM of Football, Danny Buderus, indicated that Pearce could pay for the scandal by being stripped of his captaincy.
"It's not acceptable, there's no doubt about that," Buderus told reporters on Monday.
"It's something we're all striving for … culture. Culture for us is very important; what we stand for is highly important and we need those players to adhere to that.
"There are standards in all parts of our organisation and that behaviour is not acceptable."
A decision on the captaincy has not formally been made yet, with Knights coach Adam O'Brien to meet with senior management to discuss the incident in coming days.
"Mitchell likes to be captain and if it was to go that way, it would hurt," Buderus admitted.
"So it's one of those things that could happen, but there are a variety of things that could happen.
"We still need to finalise those decisions which way we're going to go with the leadership. We're not going to be rushed."
Buderus added that the club expected Pearce to address the incident to the Knights' playing group when he returns for pre-season training this week.
"I think it definitely needs to be addressed (immediately) when he comes back … otherwise it can fester among the group," he said.
"I think Mitchell would like it that way; anyone who walks into that group needs to understand what they've all gone through and the pressure the club has been under in the (past) 12 days.
"Something probably needs to be said to move on."
While the scandal may cost Pearce the Knights captaincy, Buderus stressed that Pearce's future at the club would not be impacted.
"There is nothing for us to say he won't be a part of us in 2021," he said.
"Just because you (are or are not) going to be captain doesn't mean you won't be here.
"There's a lot of personal impact for Mitchell, professionally as well, but that's a bridge we need to cross when we get to it."