Fabregas looks set to move back to homeclub Barcelona while Nasri's future at the Emirates remains doubtful and is tipped to leave the club as well.
Giving his opinion on the speculation surrounding the star duo, Chamakh believes the club must start making plans without them.
"I think both of them are likely leaving the club," Chamakh told L'Equipe. "It's a difficult situation for the manager.
"I don't think it's a matter of money for Fabregas or Samir. I think he [Wenger] is looking for their successors and he hasn't found them. I think before letting them go he wants to find the players to replace them.
"That's my opinion about the situation. The problem is the season starts this weekend, and it's even more difficult for us.
"I think in the situation the club was in, they could have let only one leave," he said. "Especially Cesc, he wants to leave for several seasons because he's born in Barcelona. But Samir is now in a situation where he has one year left on his contract, so if they don't sell him this summer he will leave for free at the end of the season.
"Is the club ready to refuse a little bit more than €20 million to keep a good player for one season? It's strange, at a club like Arsenal, that he's now with one year left on his contract, that the club couldn't make him sign a new contract before."
Meanwhile, the Gunners have completed their second summer capture with the signing of 17-year-old Alex Oxlade-Chamberlain.