Zak Brown has admitted that time is running out to convince Fernando Alonso to stick with McLaren beyond 2017.
With his three-year McLaren-Honda contract expiring, Spaniard Alonso has revealed that he is on the market for 2018 unless the struggling Anglo-Japanese collaboration can promise him a winning car.
"What we've agreed is that we will talk about this in the summer," new McLaren executive Brown told Marca.
"Luckily summer does not start tomorrow, because I think I know what his decision would be today.
"I think we're his favourite choice, provided we can give him a competitive car.
"It's clear that in 2017 he's not going to win any championships here, so he's thinking about where he can win races in 2018. And he hopes it will be at McLaren-Honda.
"We have another nine or 10 races to show him that we will be in a position to give him a winning car in 2018."
One rumour is that Alonso has actually set a June deadline, with a new specification of Honda engine potentially set to debut in Canada.
However, Brown said: "I don't think it will be a particular race. He will look at how we are progressing generally rather than assessing a specific update.
"I think he will sit down some time in the summer and think 'Do they really have a path to give me a winning car in 2018?'"
The 2017 car has failed to yield any points this season, leaving McLaren bottom of the team rankings.
