Chelsea boss Jose Mourinho has suggested Barcelona receive favourable refereeing decisions at home.
Match reaction to follow later.
"I know the number of penalties they get at home. I know how often they play against 10 men," said Mourinho ahead of Tuesday's Champions League encounter.
He accused former Blues striker Eidur Gudjohnsen of diving to win a penalty in Barca's domestic match on Saturday.
"I am surprised with Eidur because he played in English football all his professional life," added Mourinho.
Gudjohnsen took a dramatic tumble to earn a spot-kick in the 3-0 win at home to Recreativo Huelva at the weekend.
The incident led to much criticism in Spain, with Recreativo president Francisco Mendoza criticising Barca's influence on referees.
Mourinho caused a storm after his Chelsea side met Barcelona last season, with him accusing Argentine forward Lionel Messi of "acting" to get Asier del Horno sent off.
Asked if there would be any similar incidents on Tuesday, Mourinho added: "Ask Eidur."
Our target is to finish first in the group and it's not my problem if it's Barcelona or Werder Bremen who finish second Chelsea boss Jose Mourinho
However, Barca boss Frank Rijkaard said anyone who believes his team cheat has a "poor man's mind".
"We don't need to do that," he said.
"It's almost always losers who complain about the results and it's something we have to cope with.
"I don't care what is said. We are working honestly and it doesn't affect me."
Meanwhile Messi recently posed in a Spanish publication holding a skull in Hamlet pose in what was deemed as a response to Mourinho's accusations of play-acting.
"The picture was done with a lot of respect and I was not thinking about anyone other than Barcelona when I did it," said the Argentine.
After losing to Chelsea at Stamford Bridge on 18 October, Barcelona are desperate to make up ground in Group A.
Chelsea, by contrast, need only two points to qualify for the knockout stages but Mourinho wants to collect them as soon as possible and finish top of the group.
"Our target is to finish first in the group and it's not my problem if it's Barcelona or Werder Bremen who finish second," he stated.
"We need two points. We have three matches to get what we need to qualify automatically.
"We know our last game is at home against Levski but, of course, I would prefer to qualify before the last game.
"This is a game we will play to win. We want three points."
