Mr Bailey, a 43-year old TAB bookmaker, took Guildford into his Christchurch home after the Rarotonga incident.
He's kept a watchful eye on him since then and taken him under his wing.
But he's disappointed the NZRU haven't kept close checks on him.
"Someone should've rung me every two or three months to ask if Zac was all right, if everything was going according to plan, of if I'd had any trouble? But, there was nothing.
"They could've rung me once a week if they wanted to."
Now, Mr Bailey fears that Guildford will be "ditched" and his lucrative NZRU contract torn up.
"They've just gone on record too many times saying this is his last chance," he said.
The NZRU refused to discuss details on what support it was providing Guildford.
A spokeswoman referred to the statement made by NZRU chief executive Steve Tew on Sunday which said: "As his employer, we want to ensure that the process respects Zac's right to a fair hearing so we do not wish to comment further at this stage."
His jockey girlfriend Sam Spratt was riding at Paeroa horse trials today and did not return calls.
The TAB bookmaker says his "great" young housemate was starting to "feel the strain" over what's happened.
He didn't expect the 10-cap All Black to comment until after the rugby union meeting.
His manager Simon Porter said Guildford was shame-faced about the incident and he would be seeking professional help for his drinking problem.
After the Rarotonga incident, Guildford vowed to stop drinking for a year - but shortly before the year was out, he was photographed drinking beer at Ellerslie Racecourse while watching the Melbourne Cup.
A source close to Guildford said the latest incident occurred after he had been drinking at a property for "a couple of hours" before leaving to go on a gambling and alcohol "binge".
When he returned to the house and the alleged assault occurred, he had been "completely out of control", the source said.
The victim did not want to press charges and police were not called.
Guildford owned up to the incident to Crusaders coach Todd Blackadder two days later and is being investigated by the NZRU.
The 23-year old faces a crunch disciplinary meeting with NZRU officials, believed to be later this week, to decide his playing future in the country.
Asked whether he thought Guildford should quit alcohol for good, Mr Bailey replied: "Anybody that has an issue with drinking obviously has to have a close look at it.
"The rugby culture is the rugby culture and there's always going to be a few beers involved, we know that, but perhaps it doesn't agree with Zac at a certain level."
He refused to say what exactly happened at the late-night party, but believed had been blown out of proportion.
"Young fellas make mistakes," he said, adding that he'd apologised to the alleged victim.
"Any given Saturday night anywhere around the country there will be a disagreement, or a scuffle, or a fracas, or however you want to say it, and in general terms we don't ever hear about it."
The return of his best friend Israel Dagg to the Crusaders training squad next week would be a huge boost for Guildford, Mr Bailey said.
Several Crusaders players have phoned Mr Bailey to offer support to their team-mate.
"If the rugby union are going to distance him from that support, in my opinion it'll be a huge mistake," Mr Bailey said.
"I'd hate to see him thrown to the wolves."
