Wuck confirmed Gwinn will have a scan on Saturday morning in Zurich to assess the extent of the injury.
"I think the worst we can do is speculate," he said.
"I didn't see the foul, I just know she prevented an almost-sure goal and that would be really bad for us if it is something serious, but I will not speculate. I wait for what the doctors are going to say."
Germany put the loss of Gwinn aside and their persistence paid off seven minutes into the second period when Brand cut inside on the edge of the box before unleashing a stunning left-footed strike beyond Szemik and into the top corner.
The Lyon forward then turned provider for the Euro 2022 finalists as she picked out Schuller to head in Germany's second in the 66th minute.
Captain Pajor was Poland's brightest spark and had two big chances in the second half, but denied both times by keeper Ann-Katrin Berger.
Nina Patalon's team put in a performance to be proud of in their first experience of major tournament football and despite being outnumbered, the Polish supporters never stopped singing.