BBC Sport understands Spain's two-time world champion, 38, has had talks with Renault about a possible comeback, but the team has not made a final decision.

Briatore said: "Fernando is motivated. A year out of Formula 1 has done him good. He has detoxed himself and I see him more serene and ready to return."

Alonso left F1 at the end of 2018 and plans to race at the Indianapolis 500.

Renault is the only realistic chance of even a relatively competitive seat if he chooses to come back to F1.

Last week, it was announced that Germany's Sebastian Vettel was leaving Ferrari at the end of this season, to be replaced by Alonso's compatriot Carlos Sainz.

McLaren have signed Australian Daniel Ricciardo to partner Briton Lando Norris as a replacement for Sainz, leaving a vacancy at Renault alongside Esteban Ocon of France in 2021.

At Mercedes, both Britain's Lewis Hamilton and Valtteri Bottas of Finland are out of contract at the end of this season. However, six-time world champion Hamilton is expected to sign a new deal and insiders say the team would not partner him with Alonso or Vettel.

Red Bull have Max Verstappen as their number one until 2023 and are not looking for a driver of Alonso's stature as the Dutchman's team-mate.

Briatore, who was talking in an interview with Italy's Gazzetta dello Sport, said Ferrari's decision to dispense with Vettel was understandable in the context of his being beaten by new team-mate Charles Leclerc last season.

BBC Sport has learned Vettel was never offered a new contract after discussing the team's future plans with team boss Mattia Binotto.

"In F1 it has always been about having the winning recipe," said Briatore, a former boss of the Renault and Benetton teams. "You must have one driver who is focused on the World Championship and the other who collects big points, snatching them from rivals.

"Vettel paid for the fact that a very fast boy arrived at the team. It surprised him and the team, as happened at McLaren with Hamilton [in 2007]. Two drivers at the same level in a team eventually risk taking points off each other.

"[Sainz] is a good driver, and he had a good championship in 2019 if we consider the car he had available.

"The situation seems clear to me: Ferrari is betting everything on Leclerc and it is good because, as I had the opportunity to say last year, he is a future star."

He added: "You can see the good drivers right away. I remember well the numbers that Michael [Schumacher] did, even if he was still very young, with Benetton.

"There were also the calls from [former team boss] Giancarlo Minardi to tell me about the young Alonso.

"You understand immediately if one is special, and Charles is."

However, Briatore did say that he was "a little surprised at the timing Ferrari's decision - there is still 2020 to race and here we are already talking about 2021".