Fernando Alonso leaves Formula 1 after Sunday's final of the Abu Dhabi Grand Prix season, but McLaren says he will not hesitate to use his services again if necessary.
The double world champion does not rule out returning, considering it unlikely at the age of 37, but the head of the Zak Brown team told Reuters on Wednesday that the Spaniard would be the first driver he called if there was a problem.
"We certainly would not hesitate if we needed a driver who is not one of our current two to make Fernando the first on the speed dial list," he said.
"(Michael) Schumacher is back, (Alain) Prost is back, I would not exclude it, we're very pleased with our line-up of drivers for the future – that's what we're focusing on right now – but never say never.
"He definitely goes to the top of his game."
Jenson Button, the 2009 world champion who left McLaren at the end of 2016, made a one-time return at this year's Monaco Grand Prix when Alonso was absent from the Indianapolis 500 race.
Belgian Stoffel Vandoorne also made his debut in 2016, when Alonso was injured in Australia and excluded from the second race in Bahrain.
McLaren has a completely new squad for 2019, and Spaniard Carlos Sainz joins the Renault team, and the British teenager Lando Norris becomes a substitute.
Twice the Monaco winner, Alonso, will continue in the World Endurance Championship with Toyota, winning the 24-hour Le Mans race this year, as well as with McLaren again at the Indy 500, racing the Triple Crown of Motorsport.
Brown said that Alonso will certainly participate in Formula One next year and eventually he has not ruled out a new role for him.
"He's talking about one of those days with a management shirt," said the American. "He loves being on the racetrack: when he's not on Formula One or endurance, you'll find him on the go-kart track, he can not stay away from the racetrack.
"He's still a McLaren driver, we're all Indianapolis 500, so I think Fernando has other ways he can influence and help our team."
Brown recognized the Spaniard as one of the best in his era and one who could win many more championships than his two with Renault.
Sunday's race at Yas Marina, he said, he would be emotional and also disappointed.
"It's a pity that he will not come out with a chance to win or a podium – it's probably disappointing for all of us because he drives the best he has ever driven," said the American.
"This weekend I'm sure it will be difficult to even score points."
The former McLaren champions are sixth in the constructors' standings with 62 points, of which Alonso 50 have won, who recently won the Ferrari Grand Prix in 2013 and has no podium since 2014.
"Regardless of his long career, he only won two championships, if he was in the right cars during his 17-year career, he could be in the same place as Lewis (Hamilton) and Michael (Schumacher) with the fifth, sixth, seventh, "Brown said.
Alonso would definitely win the third title in 2007, if McLaren would support his debut team-mate Hamilton, with whom he ended the season, and Kimi Raikkonen of Ferrari won one more.
Hamilton then took the title from 2008, and Alonso returned to Renault before joining Ferrari in 2010 – the year in which he led the championship to the final race in Abu Dhabi before the strategy undermined his hopes.
The return to McLaren, inconceivable after the bitterness in 2007, came in 2015, but also coincided with the worst course of the team and finally the doomed partnership with Honda, which ended last year.
TALENT SUPPORTS STATISTICS
Ferrari also has not won the driver's title since Raikkonen.
"His statistics probably do not fit in his huge talent," Brown said, rejecting the conversation about the fact that the Spaniard had a destructive influence and emphasized his intensity and hard work behind the scenes.
"I'm aware of history for all these years, but from my point of view he was a fast racing driver who wants the best equipment and the best people, and he does not accept anything but perfection.
"Working with him was a pleasure."