Xavi protested too loudly to the referee and in the end he was sent off in last week's match. I hope that Barcelona will not experience problems when Xavi is not accompanied and the assistant coach is expected to be able to do his temporary job well. It's not easy when the competition is getting tougher, especially with Girona, Barcelona has to face this and I'm pretty sure it won't be a problem. The important thing is that team unity does not decrease and that is what they must maintain.
I doubt that the absence of Xavi will have any negative effects on the team. I don't perceive him as a coach who is able and understands how to influence the game from the sidelines. An average coach like him has very limited influence on the game when he is standing at the sideline. There are world class coaches whose presence means something to the players on the field, but Xavi isn't really one of them. The communication between the main coach and the assistant coach will still be there and there are still instructions going on. It's just a different voice then.