Kai Wagner is a German professional footballer known for his role as a left-back with the Philadelphia Union in Major League Soccer. This tag page features news, articles, and updates about his career progression from his early days at SSV Ulm and Schalke 04 II to his breakthrough in MLS. It highlights his contributions to the Philadelphia Union, including helping secure the 2020 Supporters’ Shield and his selection for the 2021 MLS All-Star Game. The tag is relevant for following his ongoing impact in professional football and tracking his achievements and performances in the league.