The 26-year-old joined the club from SC Paderborn last summer, but has struggled for first-team football at the KC Stadium.
He told the Hull Daily Mail: "The problem with Nick is his adaptation to the English game. He still hasn't quite grasped it.
"We thought he was maybe ready but unfortunately the physicality is something he finds difficult, especially playing in a cup tie. They're going to throw it into the box, scrap and fight, and that's exactly what they did. Unfortunately, he finds that a struggle.
"We'll see what the options are for him going forward but he's like anyone, he needs to play. He's not getting that here. There might be an opportunity (to move) but we'll see."
Proschwitz featured in Hull's League Cup victory over Leyton Orient on Tuesday.