Chelsea have taken only 26 points from 15 games at Stamford Bridge in the Premier League this season, and have been well beaten in their last three home matches, conceding 11 goals in defeats against Brentford (1-4), Real Madrid (1-3) and Arsenal (2-4). More than enough reasons for Thomas Tuchel to express his top four spot fears.If you ask the German, Chelsea are not safe in the top four. Usually prety eloquent manager struggles to explain his team’s sudden loss of home form and their error-strewn nature.’I’m worried about the number of mistakes. In the year 2022, we already had eight big mistakes that led to goals. This is very untypical, very unusual.’ said Tuchel, as his team prepare to host West Ham on Sunday.’It costs us a lot. Not only a goal, it costs you self-confidence and belief in what you are doing. The situation is a bit fragile at the moment. Edou knows he can do better and normally does. Andreas knows it’s the right decision to play the ball back. It’s not that we take crazy risks. So it’s hard to analyse.’ said Tuchel, picking out costly mistakes by goalkeeper Edouard Mendy in the Champions League against Madrid and a mis-hit backpass by Andreas Christensen against Arsenal, on Wednesday.Tuchel blames the pitch and his players for a loss to ArsenalTottenham and Arsenal are both five points behind the Blues, although the north London clubs have played a game more. On the other end, Chelsea are a distant third to Manchester City and Liverpool.’I never feel secure in the Premier League,’ said Tuchel. ‘Nobody should. Feeling secure does not keep you on the edge. Feeling secure is very close to being lazy or not fully alert.’Sun 16:00: (1.56) Chelsea (4.30) West Ham (7.00)After an arduous campaign of 55 games — five of which went into extra time – Tuchel fears his players may be tiresome. Not only due to the physical demands but also the mental strain.’Maybe it comes back to me because I should push them and make them alert,’ said Tuchel. ‘It’s human to be tired, human to be more alert in a knockout game than normal matches.’Sometimes it’s also good, the foundation to play 60 games. At Mainz with one game a week, every game was like a cup final and the players were drained until Tuesday. ‘At Dortmund, players gave everything physically on a normal match but mentally it was not the same stress level.A duo of sport celebrities to take part in the Chelsea buyout saga’It’s OK to feel less tension in front of a normal home match in the Premier League than if you go to the Bernabeu. ‘It is maybe less tension, excitement and pressure. But it cannot lead to being less alert or having less investment. This can never happen.’We cannot run more or do more sprints and more effort than against Madrid or Brentford. There were no doubts about it as we had the physical data.’It’s a little bit like this but not in the same way against Arsenal. That’s why it’s tough to really understand the reasons why.’Chelsea welcome West Ham tomorrow (16.00) at Stamford Bridge and Tuchel hopes his lads will find a way to stabilize and bring satisfaction to the home crowd.