The fragile peace that has existed at Chelsea since the departure of José Mourinho six weeks ago is already under threat amid complaints about Henk ten Cate. It is understood that the new assistant coach has made an immediate impact since arriving a fortnight ago by taking control of the majority of the first team’s training sessions, but his methods and mannerisms have not gone down well with some members of the squad.

Ten Cate is a confident character with a reputation for plain-speaking, but his determination to assert himself appears to have turned people against him. Several players have complained privately about his perceived arrogance and brashness, while others have criticised an alleged desire for total control. The Dutchman told friends in the Netherlands before his appointment last month that he would be running the show at Chelsea.

It is also understood that Steve Clarke, Avram Grant’s other assistant, has begun to feel marginalised. The popular Scot held the fort almost single-handedly in the aftermath of Mourinho’s departure, planning and taking all training sessions for the first month, but since then he has had a more peripheral role. The pair have been able to work together effectively during matches, however, both urging Grant to change Chelsea’s system as Leicester City poured forward during the second half of the thrilling Carling Cup fourth-round tie on Wednesday.

Clarke was content to play second fiddle to Mourinho, but was assured by Peter Kenyon, the chief executive, last month that he would enjoy equal billing with Ten Cate. The first few weeks have not worked out that way, while Clarke has yet to receive an offer of an improved contract despite being told that it was imminent. The former Chelsea defender is unlikely to stay for ever as he has managerial ambitions of his own.

Chelsea’s hierarchy remain relaxed about such tension, attributing it to personalities getting to know each other and players being oversensitive. The club see Grant and Ten Cate as a “good cop, bad cop” combination, an inversion of the usual manager-assistant relationship, although where the structure leaves Clarke is unclear.

Of more immediate concern is Chelsea’s defensive frailties, with Frank Lampard telling teammates that they must improve if they want to win silverware. The absence of Paulo Ferreira for several weeks with an ankle injury will not help, although Wayne Bridge should be fit to make his first league appearance of the season away to Wigan Athletic tomorrow.

Chelsea are considering turning down the opportunity to join the G-14 group – an organisation made up of Europe’s leading clubs – when it is extended to 40 teams this month. The club have been lobbying for several years for an invitation but after finally receiving it, may choose to pursue their political interests through Uefa, with which Kenyon holds key positions on the European Club Forum and the European Professional Football Strategy Board.