Bayer Leverkusen sporting director is calling on his players to keep a clear head in the Europa League rematch against Roma on Thursday, but doesn’t want them to surpress all of their emotions. “Overdoing it is never good. You can only dominate if you play with your head and aren’t just driven by emotions,” Rolfes said on Wednesday ahead of the first leg of the Europa League semi-final tie. “But emotions are part of it and are also a driving force. We definitely have that. That’s why we’re all looking forward to going to Rome,” he added. Last season, the Bundesliga champions were eliminated by…