"My opinion is that people need to criticise the result, not the method. Before the last three games, we were among the best two teams at defending set pieces. Now, after these games, we are still among the top five teams at defending set pieces," Pellegrino told the club's official website.
"At the end you have to choose one method - zonal or man marking. We chose this one because we trust it. Both methods can be good if you focus on your job and do it properly. The most important thing is not the method - it's the way you manage the method.
"We know we've made some mistakes and we are working on this to make sure we don't concede more goals, but we defend a lot of set plays - that's why the other teams will sometimes score goals."