Guus Hiddink has urged the Chelsea squad to "look in the mirror" as they attempt to transform their faltering season.
Dutchman Hiddink was speaking in his first media conference since being appointed until the end of the season following the sacking of Jose Mourinho.
Chelsea beat fellow strugglers Sunderland on Saturday to move up to 15th in the Premier League table but remain just three points above the relegation zone.
Their appalling title defence led to Mourinho's departure and Hiddink, who led Chelsea to FA Cup success during an interim spell in 2009, believes the players should be analysing where it has gone wrong.
He said: "I shouldn't be here halfway through the season because it means that things are not going well as foreseen at the beginning of the season.
"I am glad to be back - it is a few years ago that I was last here in a similar situation and I will try to help out as I was asked. I shouldn't be here but I am - that is the reality of the situation and I am glad to be here because I worked here last time with a lot of love for the club.
"To work with the players is always a pleasure.
"On Tuesday I talked fully to the squad. I told them things happen in football and I want them to look in the mirror, not just two seconds but longer, and see how they can contribute on the way up. I told them as professionals to look in the mirror and be ultra-critical."