Vicente del Bosque, coach of world champion Spain, is concerned that the current run of Barcelona-Real Madrid games could have a negative effect on the national team.

Wednesday’s first leg of the Champions League semifinals between the two teams will be the third of four meetings in a short span between the archrivals.

“I’m worried about the quarrels between my players during these clasicos, which I hope don’t find their way into my locker room,” Del Bosque said. “Good relations inside the locker room are the basis for our future success."