They stressed the American family does not need to sell one of the world's most valuable sports clubs despite heavy debts.
As the Glazers' spokesman told Reuters on Wednesday: "Manchester United is not for sale."
Fans and a group of investors called the 'Red Knights' who are pushing for a change in ownership are, they said, forgetting one thing - despite debts of 716.5 million pounds the Glazer family does not need to sell the club.
"It's a group of fans," one U.S. banker, who asked not to be identified, said of the Red Knights group that includes former English Football League chairman Keith Harris.
"You can't do a hostile takeover of a privately held enterprise, so what are they talking about? Why would the Glazers sell?" the banker said, calling the idea a "fantasyland."
WON'T OVERPAY
The investor group, which also includes Goldman Sachs chief economist Jim O'Neill, has pledged up to 1.5 billion pounds in its bid, according to the London Times, but the Red Knights said it would not overpay.
"There's nothing forcing them to entertain selling," Robert Tillis, CEO of Inner Circle Sports said of the Glazers. "They're long-term holders. They've said that pretty consistently."
"Their history is buy and hold," said Marc Ganis, president of Chicago-based sports consulting firm Sportcorp Ltd.
"Now, it may be buy and refinance and hold, and then look at refinancing again... but they retain their assets. They don't flip them.
'FORESEEABLE FUTURE'
"I have every expectation they're going to keep Manchester United not just for the foreseeable future, but perhaps into the next generation of family members," he added.
The Glazers, who have owned the Buccaneers since January 1995, launched a bond issue last month to raise 500 million pounds in a bid to realign United's debts, which Gill has called easily sustainable.
