Chelsea boss Thomas Tuchel has refused suggestions that a lack of effort has hampered the Blues at Stamford Bridge, although he admits he is struggling to explain their poor home form.
Having fallen to a 4-2 home defeat against Arsenal on Wednesday, Tuchel's men have lost three consecutive games at Stamford Bridge after a 4-1 Premier League loss to Brentford and a 3-1 Champions League quarter-final reverse to Real Madrid earlier this month.
Chelsea host West Ham on Sunday, looking to solidify their grasp on third place in the Premier League after losing just one of their last 15 home league games against the Irons (10 wins, four draws).
Although unsure as to what was causing the Blues' Stamford Bridge woes, Tuchel refused suggestions that a lack of effort was to blame.
The 48-year-old also insisted it was normal for elite players to feel less "tension" during regular league games than in European knockout games, having watched the Blues make multiple defensive errors in their defeat to the Gunners.
"It comes back to me because I should push them and make them alert," Tuchel said. "It's human to be tired, human to be more alert in a knockout game than a normal match. Sometimes it's also good, the foundation to be able to play 60 games.
"I remember at Mainz [Tuchel's first senior management role] with one game a week, every game was like a cup final. On a Saturday, we gave 150 per cent physically but also mentally, the players were drained until Tuesday.
"Once I stepped into being coach at Borussia Dortmund, I saw that players gave everything physically on a normal match but mentally it was not the same stress level as for players at Mainz. They were capable of playing more games.
"It's a thin line in judging – that's why lazy is the wrong word. But it's okay to feel less tension in a normal match in the Premier League and a home match than if you go to the Bernabeu.
"It's normal because it is maybe less tension, less excitement, less pressure. But it cannot lead to being less alert. This can never happen.
"I don't know what it is [causing Chelsea's poor home form]. If it was just the one thing, we would switch dressing rooms or take another hotel or something like this.
"But that would maybe be more superstition than anything else. I have no solution, but it's also not the level that we want to produce in home games."
Chelsea have secured 26 points from a possible 45 in their 15 home Premier League games this season (seven wins, five draws, three defeats). Away from Stamford Bridge, Tuchel's team have taken 36 points from 16 games (11 wins, three draws, two losses).
The Blues' attempts to rectify their poor home displays could be buoyed, however, by the poor travelling record of Sunday's visitors, with West Ham failing to win a Premier League game on their travels since beating Crystal Palace on January 1, recording one draw and four defeats on the road since then.