"At training, we emptied our heads," the French international Mapou Yanga-mbiwa said ahead of their trip to bottom-placed Sochaux on Saturday.
"We laughed, we had fun playing together and we hope it will work.
"There is no real problem. There are just some times when we are not focused enough."
Right-back Garry Bocaly is back from injury while midfielder Jamel Saihi is returning from a two-match ban.