Coach Niko Kovac from ailing Borussia Dortmund has said that nothing is decided in their Champions League last 16 play-off tie against Sporting despite a 3-0 advantage from the first leg in Portugal. “It’s only half-time. I’m expecting a tough game, we’ll give 100% and not even start making big calculations. We won’t change much,” he told a news conference on Tuesday. “But it’s also an opportunity to grow together and come out stronger. We have to fill our heads with positive thoughts so that th