Luiz Felipe Scolari is facing a growing challenge to his authority from the dressing-room in light of Chelsea’s recent poor performances. The Times understands that 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.

It is not the first time that Scolari’s substitutions have been subject to scrutiny by his players. 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.

Chelsea’s run of only one win in five home league matches has brought such complaints to the surface, but there have been concerns about some of Scolari’s methods all season. John Terry and Frank Lampard went to see the manager a fortnight ago to ask if the intensity of training sessions could be increased and several others have admitted in private that Chelsea are lacking the physical power with which they used to swat opponents aside even while playing badly under José Mourinho. Another complaint muttered in private concerns alleged preferential treatment of Deco, who has remained in the side despite contributing little since he returned from a thigh injury in October.

There is also concern that some players are struggling to understand Scolari’s instructions, as appeared to be the case against West Ham. Didier Drogba, Nicolas Anelka and Joe Cole played close together in a front three after Drogba’s introduction in place of Ballack at half-time, with Scolari clearly frustrated with their performance.

The Brazilian admitted afterwards that he needs more time to work with his players on the training ground, but that is not a luxury afforded in the Premier League, when the top teams play matches every three days.

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.

While Roman Abramovich, the owner, has remained in the background, Peter Kenyon, the chief executive, and Eugene Tenenbaum, a director and Abramovich’s closest aide, have been regular visitors to the dressing-room in recent weeks. Chelsea, however, insist this is normal practice at the club but declined to comment further.

Meanwhile, the players will return to training this morning after two days off to begin preparations for the Premier League match away to Everton on Monday and — at their own request — can expect to be put through their paces.