Felix Magath has warned that the Bundesliga has become unbalanced, saying he fears a lack of competition for Bayern Munich could prove unhealthy.
Magath, one of the Bundesliga's most successful coaches over the last decade and a double title-winner with Bayern, called for the introduction of a draft system along American lines in order to make Germany's top flight more even.
But Bayern president Uli Hoeness stressed that he did not expect the Bundesliga to be a one-horse race, despite last season's runaway champions further strengthening their squad.
Speaking to Hamburg's Abendblatt on the eve of his 60th birthday, Magath said: "Bayern always apply the principle of weakening their direct opponents with transfers, and, by doing that, strengthening their position."
In April, Bayern triggered a release clause in Dortmund midfielder Mario Gotze's contract and signed the Germany star, around whom Dortmund had hoped to build their team, for €37 million.
"They have earned their supremacy with a smart policy over the years," Magath added. But he warned: "In the past, the Bundesliga drew its strength from being more balanced than other top European leagues, but this balance is no more.
"Bayern will most probably not lose a single game in the upcoming season, and an end to their dominance is not in sight. In the long run that is unhealthy – also for Bayern."
He said a draft system was a possible solution and that it was "worth considering how to create equal opportunities in the interest of the overall product".
Bayern president Uli Hoeness, however, told Bild: "The league will not be as one-sided as everyone expects it to be." He tipped Dortmund to produce a strong challenge.