Celtic have been dominating the Scottish league for a while now and Rangers have struggled to match up.
McCoist says that the Rangers board will have to break the bank for four quality players if they want to challenge Brendan Rodgers’ men next season.
He said: “Rangers will need, I would have thought, at least four players if they want to challenge Celtic for the title next year.”
The Rangers legend has also urged the club to look at the bigger picture now. Even if Rangers manage to beat Celtic this week, they must plan ahead for the next season and look to catch up with their rivals in the league.
He added: “If Rangers win the game, it will be cause for celebration for the players and the staff. But the most important thing would be an acceptance that, just because we have beaten Celtic once, that there is a long, long way to go.”
It will be interesting to see whether Rangers decide to splash the cash in the summer.
Manager Graeme Murty’s long-term future is in doubt and the club needs to address that issue before they can concentrate on transfers.