Bayern have started the season with a 100 percent record, registering five consecutive wins in the Bundesliga and opening their Champions League campaign with a victory over Valencia.

Yet despite their exploits in bagging maximum points so far, Robben warned his team-mates not to go overboard with the feel-good factor in the dressing room and not hold back in making their feelings known.

"It is important that ... sometimes there are clashes between team-mates," he told Sport 1.

"We need each other to tell the truth, and this is not always a positive."

Jupp Heynckes' side will look to extend their winning streak to seven when they entertain Werder Bremen on Saturday.