Arsenal manager Arsene Wenger fears that more players would leave the club, like Cesc Fabregas and Samir Nasri, because the club cannot match the salaries on offer elsewhere.
Arsenal are negotiating contracts with Theo Walcott, Alex Song and Robin van Persie but Wenger cannot guarantee whether he will be able to persuade them to stay.
"The gap on that front has become bigger for us so I cannot today say that if we go to the maximum we are sure to sign a player - even if we do that we are not sure. We will try, but we tried before (with Fabregas and Nasri)," Wenger was quoted as saying by The Guardian.
Wenger said it was difficult to persuade star players that a promised land does not exist elsewhere.
"We try to convince them," he said. "Our desire is there to do it and we are ready to sit down with them but after we see where we go."
Song have two years remaining while Van Persie, Vermaelen and Walcott will have only a year left to run, alongside Andrey Arshavin.
"I always said that Cesc is a bargain. With Nasri at least we got a reasonable price (25million pounds) for a player with one year to go. With Cesc we were forced into a situation because for me he is one of the best midfielders in the world and we knew that we would sell him under what he's worth (potentially £35m)," he said.