"I think it is easier to win the lottery than say who will win this season," the popular Frenchman told L'Equipe sports daily.
Mercedes is undoubtedly the clear title favourite based on winter testing and the results in Australia.
But Alesi insisted: "It will take more than three grands prix to determine which car is the most reliable.
"Today, the engines are playing a more important role than the chassis, when in previous years it was the opposite.
"I feel that for the moment Mercedes has the best engine, but it is very difficult to say more than that.
"For the drivers, I think it will be between Hamilton, Alonso and Raikkonen, but - again - nothing is certain," Alesi added.
The 49-year-old former Ferrari and Sauber driver is sure, however, that 2014 will be an exciting season.
"Yes, because we see very clearly that no team is really ready today," said Alesi.
"Even Mercedes had the technical problem with Lewis Hamilton after only a few laps in Melbourne. So nothing is certain."