By Karolos Grohmann EVIAN, France (Reuters) - Germany's defense will be put to the test in their opening Euro 2016 group match against Ukraine in Lille on Sunday with major questions still to be answered about the world champions' new-look rearguard. Coach Joachim Loew's team will be without key central defender Mats Hummels, still recovering from a muscle injury, as they kick off their Group C campaign. Hummels' replacement Antonio Ruediger was ruled out with torn cruciate knee ligaments this week. More...