By Adam Parsons
BBC sports news correspondent in Sao Paulo
Fernando Alonso has not behaved "as a sportsman" and will leave McLaren at the end of the season, says Williams' engineering director Patrick Head.
Alonso has had a fraught relationship with his McLaren team
"I would expect Alonso to either have a long time gardening next year or to go to another team," Head told BBC Sport.
"I suppose his relationship with McLaren boss Ron Dennis could be repaired, but I'd be surprised.
"I think it's unfortunate that it's got to this point, but that's the way it is," added the Williams co-founder.
"McLaren are a very, very fair team in the way they treat their two drivers.
"Fernando did not contemplate that there would be this young chap, Lewis Hamilton, who would be beating him, and he has reacted to that."
Alonso goes into Sunday's final race of the season in Brazil trailing team-mate Hamilton by four points in the drivers' standings.
And while Head acclaimed Hamilton as "a hugely impressive" performer, praising him for being "adept at avoiding problems", he was less complimentary about Alonso.
"From what I've seen, it does not look to me, or to many people in the pit-lane, as if Fernando has handled himself particularly well as a sportsman," he said.
Head also moved to dismiss speculation that Williams driver Nico Rosberg will move to McLaren as a possible replacement for Alonso.
Head claimed the team were keen to provide Rosberg with a more competitive car next season that would give him the chance to challenge for podium positions, and perhaps a victory.
A shortlist of four candidates has been drawn up for the team's second seat, following the retirement of Alex Wurz.