The midfielder's club "stands unequivocally" with Butters and will review the tribunal's findings, which will be released on Wednesday, before deciding whether to appeal the verdict.
Butters was on Tuesday evening fined $1500 after the tribunal upheld a charge of abusive and insulting language towards an umpire.
Foot alleged Butters said: "How much are they paying you?" after he awarded a free kick to St Kilda in Port's loss to the Saints on Sunday night.
Butters vehemently denied that, insisting he said "surely that's not a free kick".
Tuesday's hearing lasted an hour and 40 minutes, before the panel of Renee Enbom KC, Jason Johnson and Darren Gaspar deliberated for 25 minutes and upheld the charge.
The tribunal set itself a 5.45pm deadline and announced its verdict minutes before, with written reasoning to be distributed on Wednesday morning.
"I'm clearly disappointed with the result tonight," Butters said outside Port Adelaide headquarters.
"I stand by knowing what I said and what I didn't say, especially what I didn't say.Â
"I'd like to thank the club for the support. Thank you."
Butters wouldn't comment when asked if he would appeal.
"The club is deeply disappointed in the Tribunal's verdict and rejects any suggestion that questions Zak's integrity," Port Adelaide chief executive Matthew Richardson said.
"Zak is a man of outstanding character and we are acutely aware of the toll these proceedings take, not only for him but for his family and those closest to him."
Port have cancelled coach Josh Carr's Wednesday morning press conference, and will reschedule it for later in the day.
The Power's stand-in captain was referred directly to the tribunal after Foot reported Butters.
A free kick was given to St Kilda's Mitch Owens and Port's Ollie Wines took issue, as did Butters, who was penalised 50m and reported for abusive language by Foot.
The AFL said the exchange between Butters and Foot was not picked up by the umpire's microphone.
Tuesday's hearing relied on testimony from Foot, Butters, Wines and Port football boss Ben Rutten.
Foot insisted he had not misheard the comments and they clearly came from Butters.
"The comment that Butters made to me was "how much are they paying you?" Foot said.
Foot said he interpreted "they" as being "the St Kilda Football Club or someone involved with St Kilda".
"It questioned my integrity," he said.
"I'm 100 per cent adamant that those are the words Zak Butters said to me.
"When your integrity is questioned you don't forget those words that are said to you."
Butters was "100 per cent sure" he did not say "how much are they paying you" to Foot.
"I recall saying 'surely that's not a free kick'," Butters said.
He later added: "It hurts me because I know I didn't say it."
Butters said he was unaware Foot worked for Sportsbet and provided racing tips, a role approved by the AFL.
Wines was adamant Butters did not say "how much are they paying you" and was only questioning Foot on why he awarded a free kick.
"I can't be sure what he said but I'm adamant what he didn't say," Wines said.
"I categorically deny that's what he said. I did not hear that at all or anything remotely close."
Rutten said Butters had been confused as to why he had been reported.