Chelsea manager Jose Mourinho says his side are not leading contenders to win any trophies this season because they lack a cutting edge in front of goal.
The Blues to move two points behind Premier League leaders Arsenal ahead of their meeting at Emirates Stadium on 23 December.
"I don't think we are the big contenders of any competition," Mourinho told BBC Radio 5 live.
"We don't have the striker who is going to score 30 goals in the league."
Only five of Chelsea's 32 league goals this season have been scored by recognised strikers: Fernando Torres (two), Samuel Eto'o (two) and Demba Ba (one).
"We know we don't have that striker we used to call the killer, the selfish one, the one that gives the last touch," said Mourinho.
"You don't kill and when you don't kill you are giving a chance to the opponent. It happened to us against it happened to us against You have situations to kill and you don't, so it's difficult.
"It is a concern. We have to try to improve our defensive mistakes but I think the defensive mistakes are also a consequence of the fact you don't kill.
"When you don't kill you know you are on the edge and any mistake can lose you points. Today could finish 5-1 or 2-2 and that is hard for my heart."
When asked if he would look to buy a selfish frontman during the January transfer window, the Portuguese replied: "No. They are not available.
"They are in the big clubs, they are in the clubs with big ambitions and big clubs with big ambitions don't sell their top selfish ones."
Chelsea took the lead at Stamford Bridge through Torres before Marouane Chamakh equalised for Crystal Palace.
Ramires hit what proved to be the winner but missed two more chances late on after Stuart O'Keefe had almost pulled Palace level again.
"We got the points and we are where we want to be - two points from the leader and the next game is against them," said Mourinho.
"It's Arsenal v Chelsea always, but it's one thing if it's six or seven points difference and another if it's two points.
"There are so many title contenders and the distance in points is very small, so every game becomes a big one."