Rangers are adamant the non-arrival of Ross Wilson, who had been targeted to fill the Director of Football role, will not distract them from pushing ahead in their efforts to appoint Pedro Caixinha as Mark Warburton’s successor.
McCoist said: “I actually don’t think the manager is the biggest thing needing sorted out. It goes a lot deeper than that.
“The club needs investment. I don’t think it’s rocket science. I know a lot of people talk about Directors of Football and all that.
“In 2007, Walter Smith went back to Rangers after Paul Le Guen. He spent around £2million on Carlos Cuellar, the same on Steven Naismith, Steven Whittaker and Kevin Thomson.
“Within a year, the club was in a UEFA Cup final. Celtic thoroughly deserved their title, but, with the greatest of respect, that run probably cost us the title.
“Until there is investment, I think we will be having this conversation next year and the year after”
Ex-boss and club record scorer McCoist said: “It’s just a fact the club needs financial investment.
“Have we moved on? Were we good enough then to challenge Celtic? No chance, absolutely no chance.
“There was the crash. I know for a fact the debt at Rangers Football Club at that particular time was 100 per cent manageable.