Rangers supporters are tormented by their imagination.

In the midst of the financial turmoil at Ibrox, the old certainties, of the existence of their club, of its stature, of its means, have been dismantled, and many of the potential scenarios the fans can envision are dire.

The following is so vast that it is difficult to imagine, in the worst possible case, that supporters would not collaborate in the formation of a new team, even if it would mean beginning in the lower reaches of the game, like AFC Wimbledon or FC United of Manchester. That is an extreme outcome, but the prospect of a Clydesdale Bank Premier League competition that did not involve Rangers would be a delight to only a small hardcore of rival fans.

It is a fact of Scottish football life that the Old Firm generate revenues that help to sustain the game. This rankles with supporters of other teams, who believe that Celtic and Rangers are too dominant and that the viability of their own club should not depend on the two Glasgow sides. Many fans grow peeved at the Old Firm, but the demise of Rangers would be a source of consternation beyond the perimeters of Ibrox.

There is a widespread judgment that Rangers are paying the price for the hubris and vanity of Sir David Murray, and Craig Whyte's willingness to exploit the circumstances he encountered. These views grow increasingly persuasive. There is a moral argument for the Ibrox side having to pay a heavy price for years of reckless financial mismanagement, but other considerations will also influence their fate. In contemplating a future without Rangers, the directors of the remaining SPL sides would have to consider their own imperatives rather than broader ethical arguments alone.

Even if Rangers fail to move out of administration and a new company is born with the old assets of Ibrox, Murray Park and the current playing staff, the SPL would need to agree to readmit them to the league. This would be voted on by the board, comprising Neil Doncaster, the chief executive, Ralph Topping, the chairman, Stephen Thompson, of Dundee United, Derek Weir, of Motherwell, Eric Riley, of Celtic, and Steve Brown, of St Johnstone. This turn of events cannot be considered inevitable, but it would be remiss of the figures involved not to have at least thought of the consequences.

"I've looked at the different income streams and how they might be affected," says Stephen Morrow, the head of Sports Studies at Stirling University. "It must have an effect, there can't be any doubt about that. The title sponsorship of the SPL was originally worth £8m per annum, is probably up to £10m by now and expires at the end of next season. Now, the Irn-Bru title sponsorship of the SFL is worth £1m. I'm not suggesting that simply by removing Rangers from the SPL you go from £10m down to £1m, but there's one source of income that is about a product that has the two [Old Firm] teams in it.

"That relates to television, as well, and part of the reason [Sky] will pay the sort of sum that they do will be dependent on having four Old Firm games. If the contract is renegotiated and there is less coverage of Scottish football as a consequence, and so a smaller market, then that will not only have an impact on the TV deal but also sponsorship. Part of the attraction for the Clydesdale Bank was that they would be associated with these Old Firm matches, which were broadcast on Sky. You see an immediate problem with the TV deal and the associated deals, like sponsorship."

Many fans assume that other clubs will seek to castigate Rangers. Rivalries will always exist, but there are practical concerns that must also be faced. No chairman is prepared to address the prospect until it happens, at least publicly, and many are still weighing up all the significant factors. Teams that had to drastically restructure when the Setanta TV deal collapsed will not wish to face another radical change to their financial model. As well as the effect on the television and commercial deals, the loss of Rangers to the SPL would reduce the income clubs make from ticket sales.

"If you then compare the difference between a non-Old Firm club's highest attendance and the average attendance, then multiply that by a fairly average £20, you get quite a big drop off in income," says Morrow. "Take Kilmarnock for the sake of argument, comparing the highest attendance with the average, they would lose £85,000, just like that. Celtic and Rangers aside, all the clubs have been working hard to get to something that looks like a sustainable model and they're running very tight margins, so they would struggle with too many more diminutions of the income while surviving as full-time clubs. This isn't an industry that can afford to lose paying customers, because it's operating in the margins anyway." A balance would have to be struck between these commercial implications and applying justice.

Celtic might not suffer undue hardship in the immediate aftermath of Rangers being removed from the SPL, but longer-term they would be diminished by the lack of a serious competitive rival. It is the nature of the Old Firm game, the intense emotions and commitment it provokes, that became a source of wealth to Rangers and Celtic; the clubs grew because of their hostility to each other.

This tension has driven the two clubs to their heights. Without it, Celtic would eventually downsize. There is little prospect of Parkhead being filled each week while the team enjoys a procession towards the title. Without the Old Firm games themselves, fans would be robbed of the matches that stir within them the greatest passions.

"I really think that we need Rangers," says Stevie Chalmers, the Lisbon Lion. "You were always looking forward to the Rangers games, the Old Firm games were just terrific. I wouldn't like to see the league without Rangers, although that doesn't mean I want to see them beating us. It's a terrible thing they've got themselves into. But you couldn't imagine the league without the two Old Firm teams in it."