Guus Hiddink has warned Chelsea's players they will face the axe if they do not show "great desire" to reverse the club's miserable Premier League fortunes.
Chelsea's new interim manager revealed he told his Blues squad to "look in the mirror" to account for their part in Jose Mourinho's departure.
Hiddink has not ruled out helping Chelsea identify Mourinho's long-term successor, but refused to be drawn on whether their former striker Didier Drogba would join his back-room staff.
Mourinho left Stamford Bridge last week with Chelsea technical director Michael Emenalo citing a "palpable discord" between the Portuguese and the players after nine defeats in 16 league matches.
"I spoke fully to the squad and of course we talked a bit about the past," said Hiddink ahead of Saturday's clash at home to Watford.
"Why I'm here, the reasons why we are down.
"But on the other hand I told them things happen in football and I want everyone to look in the mirror, not just for two seconds, but longer.
"And see what anyone can contribute from now on to raise us up. That was what I was emphasising, not to look back too much.
"We cannot ignore what has happened in the recent past, but I asked them and told them to look in the mirror and be hypercritical and give the best for the team.
"They have to look forward.
"There must be a great desire to play, yes?
"If you don't have that desire, please knock on my door and we'll talk - we'll talk briefly."
Hiddink does not expect to remain at the club far beyond the end of the current season, as he reprises the caretaker role he first held in 2009.
The ex-Russia manager could help Chelsea chase Mourinho's successor, with the likes of Pep Guardiola, Diego Simeone and Antonio Conte reportedly in the frame.
"At other clubs in the past I've been speaking from time to time with the board, but not in an official capacity," said Hiddink, hinting at helping Chelsea's board in their permanent manager search.
When asked if he would consider seeking the full-time job himself, Hiddink replied: "We spoke about until the end of the season.
"First we said let's go to mid-May and then let's see. I will see what will happen.
"As long as I feel desire, as long as I feel passion (to do the job) - I must feel inside my heart that I'm passionate to work with the guys.
"You've got to have a feeling inside your stomach you want to work with the team."
Drogba sat alongside Hiddink and club owner Roman Abramovich in Saturday's 3-1 league victory over Sunderland at Stamford Bridge.
The 37-year-old continues to be linked with a role in Hiddink's short-term set-up, despite remaining contracted to Montreal Impact in Major League Soccer.
Hiddink reiterated his admiration for Drogba, but insisted the club's board would handle any extra back-room recruits.
"I worked with him five or six years ago and I was delighted to have such a professional in the squad," said Hiddink.
"He's a legend already in this club. It's nice to connect guys with big hearts somehow to the club.
"The only thing is at the moment is that he's playing in Montreal.
"All clubs have specific guys who can do whatever they like.
"I think it's important that they give the Chelsea brand a big image worldwide."