Onana has popped up onto the radar of several English clubs this summer and West Ham failed with an offer for him earlier this month.
Lille do not want to sell Onana and have been clear only a large proposal could force a rethink.
The club are already thinking through what it could take for them to part ways with the highly rated midfielder.
According to French sports daily L’Equipe, Lille feel the amount PSG paid for Vitinha this summer, a fee of €40m, would be appropriate for Onana.
If Lille did sell Onana then they could use a portion of the fee to reinvest in the transfer market.
It remains to be seen whether West Ham would be willing to go up to €40m in order to land Onana during this summer’s transfer window.
Lille only snapped Onana up last summer and have him locked down on a contract running until 2026.
