The Kroos brothers admit there could be some rivalry this season.
Real Madrid midfielder Toni Kroos will meet Germans Union Berlin in the Champions League - a former club of brother Felix.
"Of course, I have to say that the family always comes first. But I have a problem because Union is my football family, so it's not that easy and I don't want to commit yet," explained Felix.
Toni, meanwhile, said: “These are relatively pleasant and short trips. You have Germany, Portugal and Italy and from here it's always quite nice.
"But I know to be wary a little about the Union. I know them yes. I have already seen some matches of them."