Brawn dismisses Schumacher quit rumours
Michael Schumacher is thinking about pulling out of Formula 1 at the end of this season, according to BBC Sport pundit Eddie Jordan.
The German, 41, ended three years in retirement when he signed last winter a three-year deal to drive for Mercedes.
"I've a hunch something fundamental has changed. I believe he is disillusioned and thinking of quitting," said Jordan.
However, Mercedes boss Ross Brawn told BBC Sport: "[There will be] no changes to the driver [for next season]."
Schumacher's manager Sabine Kehm also told BBC Sport: "Michael has no plans to quit at the end of the year."
Schumacher reflects on comeback so far
Schumacher has struggled this year and has been comprehensively outperformed by team-mate
with experts saying he has been unable to adapt his driving style to the particular characteristics of the Mercedes car and the tyres used this year in F1.
He has also come under fire for his driving - most recently when he was
punished by the stewards for almost pushing Williams driver Rubens Barrichello into the pit wall at the Hungarian Grand Prix in August,
a move that earned him a 10-place penalty on the grid at the next race.
Jordan said: "There are too many indications that now give me the feeling he is reconsidering his commitment to his three-year contract.
"There is far too much movement in the Mercedes motorhome involving managers from drivers from other teams.
"I have heard rumours that (team principal) Ross Brawn's continuity with the team is in doubt, which would be a huge blow.
"It's also rumoured that as a result of the lack of performance of the Mercedes car, expectations for next year within the team are not as high as they were at first.
"The Barrichello incident had an effect - he hadn't realised driver standards had changed so much, and that has surprised Michael.
"My guess is Michael has probably come to the conclusion that, despite his undoubted brilliance, just like this year he's not going to be able to drag that into being a winning car."
It is a three-year project to build a winning team and he is in the middle of the process
Schumacher's spokeswoman Sabine Kehm
Jordan also pointed to an interview Schumacher gave BBC Sport at the Belgian Grand Prix two weeks ago in which he admitted it was impossible for a 41-year-old to perform at the same level as the younger drivers he is competing against.
Schumacher said in that interview: "At the end of the day there are physics. How can a 41-year-old be as good as a top level 23 or 24-year-old?
"But I have experience and a high level of speed.
"If it is exactly the same as at my high periods in Ferrari I don't think we will ever know. Because when I had that with Ferrari I had been working for 10 years to make that level. This time I have been with a whole new team just for one year."
Kehm denied Schumacher had any doubts about his commitment to F1.
"Michael is fully geared for next year. When he entered into the whole comeback scenario, he was fully informed about the situation with the car," she said.
"That's why Michael chose it to be a three-year contract - you cannot expect to come back and win straight away in that situation.
"That's why he is not frustrated at all.
"Obviously he would have wished that the developments to the car improved its performance more than they did.
"But it is a three-year project to build a winning team and he is in the middle of the process."
The doubts about Schumacher's situation have arisen at a time when there has been tension within the Mercedes team between Brawn and Mercedes vice-president of motorsport Norbert Haug.
BBC Sport's online F1 editor Andrew Benson said: "The car's lack of performance puts Mercedes in a difficult position. Because Schumacher is such a legend in Germany, the company is unable to blame him for any lack of performance, even though he is being outpaced by Rosberg.
"That means Mercedes have to blame the car - and they are unable to replace Schumacher with a younger driver who might be faster because of his firm contract.
"These issues, combined with the team's lack of progress this season, have led to disagreement between Haug and Brawn about the future direction of the team - and there have been rumours that Brawn could end up leaving.
"Brawn worked with Schumacher when he won on all his seven world titles, two at Benetton and five at Ferrari.
"Haug has known Schumacher just as long - Schumacher started his top-level international career driving sportscars for Mercedes in the early 1990s."
Haug denied at the Italian Grand Prix that he and Brawn were at loggerheads.
"We are absolutely together working on next year's car," he said.