Stiliyan Petrov has claimed Rangers are no longer a big club after their latest humiliation at the hands of Celtic.
Brendan Rodgers' side thrashed a hapless Gers 4-0 in the William Hill Scottish Cup semi-final at Hampden Park on Sunday, their 13th Old Firm meeting unbeaten.
It has been another season of turmoil for the Ibrox club, who sacked manager Pedro Caixinha earlier in the season before failing to lure their primary target Derek McInnes away from Aberdeen, which resulted in Graeme Murty taking the job until the end of the season.
The club suspended experienced duo Kenny Miller and Lee Wallace yesterday following an alleged exchange with the manager and have fared little better on the pitch in recent weeks with just one win in their previous five matches.
That has seen them drawn into a battle for a top three finish behind Celtic by Aberdeen and Hibernian, which Petrov says is damning about their current plight.
"At the moment people don't take Rangers as a threat, it's more Aberdeen or Hibs, Rangers are not one of the biggest clubs," said Petrov.
"People say Celtic v Rangers will always be one of the big rivalries, but if Rangers don't challenge, it will lose its intensity and it's important for Scotland.
"That's what Scottish football is all about - the Old Firm - and that's why people all around the world love Scottish football.
"If that doesn't come back, it will be very difficult for Scottish football to recover."
The former Hoops midfielder admitted that he does not see Murty as the man to close the gap on Celtic, who are set for a seventh league title in a row, but is keen to see the competition between the two to improve.
He said: "I think it's still a big gap and a long way to go for Rangers.
"As a Celtic fan, I am delighted because more success for Celtic is better, but it's not healthy for Scottish football and Celtic as well, because they need someone to compete with.
"One big club in a competition is not interesting, you need another few clubs to compete and make sure the league will improve, but at the moment it's just a one horse race."
He added: "At the moment Celtic can drop 10-15 points without a problem and still be champions.
"Before, we knew that if you drew or lost a game, that was the end of it and that was what kept us on our toes or in the European games, because we had to be on top form every single week.
"At the moment I don't think Celtic have been pushed or been challenged."