Chelsea boss Luiz Felipe Scolari is facing a challenge to his authority by his own players, it has been revealed. The Times says the Chelsea manager was asked to explain his substitutions by several senior players after the 1-1 draw at home to West Ham United in the Barclays Premier League on Sunday.

Chelsea's players have a genuine fondness for Scolari as a man, but there are increasing concerns over certain aspects of his management. The latest worries to emerge centre on Scolari's substitutions against West Ham, with several players demanding to know in a dressing-room meeting why Michael Ballack was replaced at half-time rather than the underperforming Deco, who stayed on for the entire 90 minutes.

Also, it is understood that in the aftermath of last month's 2-1 home defeat by Arsenal, several players asked sarcastically whether Scolari was aware that Chelsea were chasing the game rather than attempting to hold on, because they were unimpressed by his decision to bring on the inconsistent Florent Malouda and inexperienced Miroslav Stoch for John Obi Mikel and Deco.

Scolari retains the support of the club's board - as well as some measure of sympathy given the injuries he has encountered this season - but it is open in admitting that results have not been as good as was expected when he was appointed last summer.