Slavisa Jokanovic told Fulham to be brave and highlighted a collective responsibility to improve after another heavy defeat saw the strugglers equal an unwanted Premier League record.
Saturday's 3-0 loss at home to Bournemouth, which saw captain Kevin McDonald sent off, was a fourth consecutive top-flight defeat for Jokanovic's side.
They have conceded 15 times in that run and let in a total of 28 after 10 games, equalling the worst defensive record at this stage in Premier League history.
Jokanovic had approximately £100million worth of players added to his squad in the transfer window but has been unable to shape a cohesive unit, using a third goalkeeper of the campaign against Bournemouth by handing Sergio Rico a Premier League debut.
The head coach acknowledged improvements have to be made if Fulham are to avoid an immediate return to the Championship following last season's promotion.
"It's not question about being surprised, it's question about doing everything to make one step forward," Jokanovic told a news conference.
"We are fighting for this level and we know before we started competing it will be hard, but everything is in our hands and everything depends on us, [the] solution is between us.
"It's hard for me, for the people and board of the club, our supporters and my players too. But the solution is here around us and we must be brave, keep going forward and force ourselves to make this step."
Asked what Fulham need to do to tighten up at the back, Jokanovic highlighted defensive errors after Timothy Fosu-Mensah conceded a needless penalty to allow Callum Wilson to give Bournemouth a first-half lead.
"Working - we keep going forward, being brave, support each other, we tried to do something and tried to show different attitudes and tried sticking altogether and be organised and we tried working off the ball with many players, but we conceded easy goals," Jokanovic added.
"From my position, I miss the power, strength, speed. Bournemouth were not an easy game - they offer one professional performance and are working together and were more solid, organised and they punished us after many challenges where we weren't at a good level.
"This is the Premier League - everything is faster, more power, more strength, we need to adapt ourselves for this situation.
"I don't need to talk about individual mistakes, we need to try to make organisation and if somebody makes mistakes, we pay the expensive price, but the second goal we lost three challenges and didn't defend good enough and they score the goals.
"We must be 100 per cent concentrated to cut this out."
Ryan Fraser created second-half goals for David Brooks and Wilson as in-form Bournemouth moved a point behind the Premier League's top four.
"It's been a great start, I'm really pleased with how the players have done this season," said manager Eddie Howe.
"We're in a good place and confidence is high but we can't look too far ahead. We go into a cup game on Tuesday [at home to Norwich City in the EFL Cup] and then into a big one with Manchester United next weekend.
"The expectation I place on myself every season is very high. I'm very pleased, but there's still a long way to go."
