Abidal, who was released from Barcelona at the end of last month, has long been linked with a move to Monaco, but has said that clauses in his contract due to his medical history have made finalising the deal difficult.
"The wait is difficult," Ligue1.com quotes Abidal as saying. "Everyone's worried about my health. I've been to the USA to see specialists and have been cleared to play sport.
"Everything is fine physically, but there have to be lots of clauses in the contract. Everything depends on AS Monaco - they're my preferred club.
"The longer things go on, the more I begin to doubt; but I'm still optimistic. In concrete terms, I don't have a contract yet, and there are other clubs who are interested in signing me. If things don't come to a conclusion, I will have other opportunities."
Nice have also been linked with an interest in Abidal.