Lyon president Jean-Michel Aulas bemoaned Paris Saint-Germain's potential signing of Kylian Mbappe as a potential body blow to competition in Ligue 1.
French giants PSG are reportedly close to signing Monaco's teenage sensation Mbappe, having already smashed the transfer record to lure Neymar from Barcelona.
There is speculation that PSG forward Lucas Moura could move in the opposite direction.
Outspoken Lyon boss Aulas, who has already been critical of Neymar's €222million arrival, warned Mbappe's potential move to Paris would severely impact the competitiveness of Ligue 1.
"If you stack the best players in a team, you do not have any more competition," Aulas told RMC as he highlighted PSG's 6-2 rout of Toulouse, in which Neymar scored twice and set up two others.
"When we see the game on Sunday night, is it useful that Mbappe comes to the PSG?
"Is this useful for the competition and for the economic development of football?
"If you no longer have an equilibrium in terms of investors, eventually you risk not having this great football as seen with PSG.
"I'm afraid that we get into a bicep surge, which is not useful. Will it improve the performance of PSG as Mbappe comes? If you stack, with supernatural money, the best players in a team, you do not have any more competition.
Aulas also confirmed Lyon – who are unbeaten after three matches – are interested in signing PSG midfielder Grzegorz Krychowiak, who is surplus to requirements at Parc de Princes, having only joined from Sevilla last season.