Chelsea boss Jose Mourinho will only consider selling Mohamed Salah if they can find a replacement.
Besiktas president Fikret Orman confirmed the club were in negotiations with Chelsea over the purchase of the 22-year-old, while Inter Milan and Roma have also registered an interest.
"He can't leave, I have 20 players today with Didier [Drogba] a bit ill and [Cesar] Azpilicueta injured," the Portuguese manager said.
"I had all my players here today, just [Nathan] Ake in the stands.
"I have a very short squad, I need everybody. For Salah to leave someone has to come, and I don't think we are going to let Salah go on loan and then spend some money to bring somebody else in.
"So I don't think so, unless my club comes to me and says Salah goes on loan and we are going to buy a £50million player."