Pearce told The Daily Telegraph it had been postponed and not cancelled.
"I'm filthy about people spreading rumours," he said.
Knights great Buderus condemned Pearce's actions.
"It's not acceptable, there's no doubt about that," Buderus told media 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."
Knights coach Adam O'Brien and senior management are set to take the captaincy from Pearce, a veteran of 297 NRL games.
Buderus was tight-lipped about the decision but did not rule it out.
"Mitchell likes to be captain and if it was to go that way, it would hurt. So it's one of those things that could happen, but there are a variety of things that could happen," he said.
"We still need to finalise those decisions which way we're going to go with the leadership. We're not going to be rushed."
Pearce is expected to deliver an apology to the playing group when he returns to pre-season training later this week.
"I think it definitely needs to be addressed (immediately) when he comes back … otherwise it can fester among the group," Buderus 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."
Buderus shot down suggestions the scandal could affect the team's pre-season.
"I don't think it will; they are paid professionals," he said.
Buderus also stressed that Pearce was still wanted at the Knights but admitted the scandal could affect contract negotiations with the former NSW Blues representative.
Pearce's current $1 million-a-season contract ends after the 2021 season. The Daily Telegraph reported that he was offered a two-year extension that halved his salary before this latest scandal.
"We do (want Pearce here). There is nothing for us to say he won't be a part of us in 2021," Buderus said.
"Just because you (are or are not) going to be captain doesn't mean you won't be here.
"We're still going through that (contract renegotiation) process. There's (going to be) a lot of personal impact for Mitchell, professionally as well, but that's a bridge we need to cross when we get to it."