Even with McLaren rumoured to be splitting with its hapless Japanese engine supplier, perhaps within weeks or months, Alonso is openly contemplating a change of team for 2018.
"I think Fernando loves the atmosphere here at McLaren and I don't think there's another team that he would prefer to drive for more than us," Brown, the new McLaren executive, told Spain's AS newspaper.
"But he wants to compete for the top positions and I understand that," the American added.
"There is zero tension between Fernando and McLaren. The relationship has never been healthier," he said. "He is frustrated but we are together in our frustration."
However, Brown acknowledges that convincing Alonso to stay beyond this year will be difficult.
"We have been clear that we want him to stay and he was very clear when he said he wants to stay," he said. "But we need a better race car, and that is where all of our attention is."
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