Bayern Munich winger Arjen Robben has questioned the mix inside the Arsenal dressing room.
Bayern face Champions League opponents Arsenal.
He told The Sun: "Of course you need that but I don't know whether they have that at Arsenal.
"But in a team you need a good mix of personalities with good characters.
"When I was at Chelsea we had some great characters in the team and that's something you learn from.
"At the time I was still very young and for my development it was a good experience to work there with such big characters."