Slavisa Jokanovic described Fulham’s recent results as “not acceptable” after they were beaten 2-1 by QPR in the west London derby at Craven Cottage.
Sone Aluko missed a penalty in the final seconds of the match – after Tom Cairney had seen an early spot-kick saved by Rangers keeper Alex Smithies.
Fulham were also denied by the woodwork and were guilty of some appalling misses.
It means Jokanovic’s side are without a win in seven matches and have suffered three consecutive home defeats.
“It is very frustrating. We’re not clinical in the opposing box or solid enough in our box,” said the head coach at his post-match press conference.
“It was a strange game and what we deserve or don’t deserve is not important – only the result is important and I accept my responsibility that we didn’t win a point.”
Jokanovic added: “We have to be more solid in defence and have more quality and find an end product.
“It’s not an easy situation for us. We have many new players and they need to take responsibility. This is not France, Belgium or Spain; this is the Championship.
“It is not acceptable. We need to show more character, personality and quality.”
Meanwhile, Jimmy Floyd Hasselbaink said he felt like he had been “fighting everybody” after a difficult week for the QPR manager ended with a dramatic win.