Former Celtic midfielder Stiliyan Petrov has claimed that the lack of competition the club faces domestically is "unhealthy" for Scottish football.
The Hoops are on the verge of securing a seventh league title on the bounce and have the chance to win a historic double treble this season.
Petrov, however, believes that the game north of the border is in danger of stagnating due to the Glasgow giants' dominance.
"One big club in a competition is not interesting," BBC Sport quotes Petrov as saying.
"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.
"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."
Petrov won four league titles, three Scottish Cups and three League Cups during his time at Celtic.
