"Zero percent," team boss Jean Todt told reporters after Sunday's Japanese Grand Prix when asked about the Spaniard's chances.
"We have two fantastic drivers in Kimi (Raikkonen) and Felipe (Massa). We are very happy with them and they are under contract.
"I would respect a contract for a guy cleaning the floor, so you can imagine that I will respect a contract with them," added the Frenchman. "If we have a contract, we respect it."
Alonso's future is subject to considerable speculation, even though he has a contract for next year with McLaren.
The 26-year-old has been linked in the media to a return to Renault or a move to Ferrari after being refused special treatment at McLaren.
His McLaren team mate Lewis Hamilton, winner on Sunday, fanned the flames before the race when he told British reporters he would rather see Alonso at Ferrari next year than remaining where he was.
Despite his comments, Todt told Spain's El Pais newspaper in an interview that he admired the McLaren driver and did not rule out an eventual interest in him.
"People have said that while I'm at Ferrari, Alonso can't come. That's not true," he was quoted as saying.
"I never said that. It wouldn't be right. I am employed by Ferrari. If at some point I knew Ferrari was interested in signing Alonso, I'd say okay. I wouldn't oppose it. My principal interest is Ferrari."
Todt said he had not been impressed by Alonso's attitude when the Spaniard was racing in the junior F3000 series but that had now changed.
"I didn't like the way he acted with me. But since then he has won two world titles and he's now fighting for the third," said the team boss.
"He's got a lot better. He's strong physically and mentally. As a driver I have great respect for him so I say 'never say never'."
(Additional reporting by Jane Barrett in Madrid)
