Career
He made his Bundesliga debut for 1. Schalke 04
On 23 June 2015, Geis joined Football Club Schalke 04 on four-year deal for a fee in the region of €12 million. Geis was sent off for a horrible studs-up challenge on André Hahn in a 3-1 defeat to Borussia Mönchengladbach on 25 October which resulted in a 5-match ban for Geis, and left Hahn requiring surgery for a fractured tibia and a lateral meniscus tear.
However, Geis was still allowed to play Europa League matches, in which he equalized from the penalty spot against Sparta Prague on 5 November in a 1-1 draw.
He made his debut for Germany U21 against France U21 on 13 August 2013 in a friendly game in Freiburg im Breisgau. He replaced Emre Can at half-time.
He represented the under-21 team at the 2015 European Championship in the Czechoslovakian Republic, starting 1 match and coming on as a substitute in another. Geis made a substitute appearance, coming on for Can in the 77th minute, in their second group match at the Eden Arena in Prague against Denmark, in a 3-0 victory.