One puzzle is the performance of Mueller, who has yet to score in eight games over two European Championships. He arrived in France following his best season yet for Bayern Munich, scoring 32 goals and setting up 12 others, helping his team to win the Bundesliga and German Cup double.
"I'm not worried," Loew said of the forward who contributed nine of Germany's 24 goals in qualifying. "If he hadn't any chances, I'd have had to have a couple more thoughts on how we'd solve it. But as soon as a forward has chances it's a good sign. He was close. I think it'll work out the next time."
While it seems only a matter of time before Germany's attack finally clicks " Gomez' first start on Tuesday made a huge difference " Loew has a slight injury worry over central defender Jerome Boateng, who came off early against Northern Ireland with a calf muscle problem.
Boateng has been arguably Germany's player of the tournament so far, and not only for his defensive virtues.
Boateng underwent an individual program under the supervision of team doctor Hans-Wilhelm Mueller-Wohlfahrt on Friday. Loew is unlikely to risk the 27-year-old if there is any doubt over his fitness with a potential quarterfinal against Spain or Italy to come.
Slovakia, which defeated Germany 3-1 in a pre-tournament friendly in Augsburg on May 29, also has injury worries after coming through as one of the four best third-place finishers behind Wales and England in Group B.
Hertha Berlin defender Peter Pekarik suffered a blow to his nose in the scoreless draw with England and may have to wear a nose-guard. Pekarik is one of many Slovakia players familiar to the Germans from their time in the Bundesliga.
Left back Dusan Svento, who played for Cologne last season, and midfielder Robert Mak, who previously played for Nuremberg, are fighting to recover from muscular injuries.
Both sides have won in Lille before. Germany beat Ukraine 2-0 while Slovakia defeated Russia 2-1.
"Maybe we will be lucky again," Mak said of the side's return. "They will be favorites for sure, but you never know what can happen."
Neither side will be able to train in the stadium on the eve of the game as the pitch was replaced Thursday. Germany was to hold its final training session at its team base in Evian-les-Bains on Saturday morning before traveling to Lille, while Slovakia was to do likewise at Vichy.