Koeman has been speaking to the press ahead of his side's matach against league leaders Real Sociedad on Wednesday at the Camp Nou.
The Dutchman was keen to dispel any rumours about problems behind the scenes, insisting that his players are very united at present.
"I see a good atmosphere in the squad, in training and matches. I don't see any problems between the players," said Koeman during his pre-match press conference.
"Yesterday they threw a Christmas party after training. There was a great atmosphere and drink flowing."
The clash on Wednesday is a huge one for both sides and Koeman spoke positively about the visiting side and expects a good match.
"They are a good team. You can tell they've been playing together for a few years," said Koeman.
"I like how they play. I'm aware we'll have to play well, with confidence and possession to cause them problems.
"I think it will be an open match, last year it was open. Both teams want to have the ball and press so I expect a nice, open game."