Manchester United captain Wayne Rooney and vice-captain Michael Carrick are among the senior players who have complained to Louis van Gaal about his training methods, according to reports.

The pair, according to the Daily Mail, approached the Dutch coach earlier this season with the paper quoting a source that told them some players 'feel like robots' under his rigid approach.

"Nobody is allowed to take a chance," a source is quoted as saying. "They feel like they are wearing straitjackets. Everything is in zones. It's a case of 'you can only go this far'. The feeling is that they are being turned into robots."

Senior players are said to be unhappy at Van Gaal's 'rigid' methods (Getty Images)

United have been criticised by fans and observers so far this season for their lack of attacking flair that has brought just three goals in their first four matches. Rooney is yet to score this season, a drought that stretches back 10 games into the last campaign.

Van Gaal admitted on Wednesday night that he didn't believe Manchester United would win the Premier League title this season, despite there still being eight months of football to play.

The disharmony at the Carrington training complex has also, according to the Mail, spread to the non-playing staff who have been banned from eating with the players and have to have their lunch in a separate room.

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Rooney and Carrick are said to have approached Van Gaal after the opening-day win against Spurs, with the players concerned they their attacking threat had been suppressed, that the players were not enjoying their football and that the manager's methods are partly to blame.

The source continued: "It was all a big family under Sir Alex.

"They all ate in the same place, from the tea lady to Wayne Rooney - but that's gone now. The hoi polloi have to pick up their lunches on a tray and go elsewhere."