[1][2] The son of former professional basketball player Marc Suhr, a 7-foot center who won four caps for the German men's national team during his career, Kratzer started out with BBC Bayreuth’s youth team at age 12,[3] moving on to the Brose Bamberg youth program in 2012.

Representing Bamberg's development squad Baunach Young Pikes, he made his debut in Germany's third-tier ProB during the 2013-14 season, helping the team win promotion to ProA that year.

Kratzer made his first appearances in Germany's top-flight Basketball Bundesliga for Bamberg in the 2016-17 campaign, while still being a regular in the reserve team.

Averaging 14.6 points, 12.7 rebounds and 1.5 blocks a game for Baunach in 2016-17,[4] he garnered ProA Player of the Year honors.

[8] In 2023 Kratzer won the Basketball Champions League with Bonn, remaining scoreless in the final against Hapoel Jerusalem, but contributing a team-high six rebounds.