Lyon president Jean-Michel Aulas has been told that it would be dangerous to pursue his interest in Samuel Eto'o.
Aulas revealed last week that he was considering a move for the Cameroonian striker, who looks set to leave Barcelona this summer.
Eto'o's agent Joesp Maria Mesalles revealed on Monday that Lyon had yet to make an official approach for the player.
And Aulas' special adviser Bernard Lacombe has now warned Lyon against trying to sign the 27-year-old.
"Eto'o is just a dream. 25th July is not 25th December, is it? We have to remain serious," Lacombe told France Football.
"A man like that earns 6millions euros (£4.7million) a year. If we sign him, every other player at the club will go to the chairman's office to ask for a pay rise."
It seems highly unlikely that Eto'o will now join Lyon, but Lacombe has confirmed that Argentine forward Diego Milito is a possible target.
Milito has been linked with a move away from Real Zaragoza following their relegation from the Primera Liga.
Lacombe said: "Indeed I talked about him with coach Claude Puel last week. But we won't rush. We have until 31st August to act."