Kratz joined Atlanta United from Philadelphia Union on Dec. 11, 2016 in exchange for a fourth round pick in the 2020 MLS SuperDraft. He made 20 appearances and five starts in MLS in 2017, scoring one goal and adding one assist. In 2018, Kratz made two starts and 27 appearances, and scored two free kick goals April 28 in a win vs. Montreal Impact to become the first player in MLS history to score two goals from free kicks in the same match after coming on as a substitute. Prior to coming to the U.S., Kratz spent his entire career in Germany, where he made 277 career appearances, with 122 of them coming from either the Bundesliga first or second division. He began his professional career with Bayer 04 Leverkusen's youth system, and has since played professionally for Alemannia Aachen, Eintracht Braunschweig and SV Sandhausen.
2018 (Atlanta United): Kratz made 27 appearances and two starts. The midfielder scored two goals, both of them coming on Apr. 28 against Montreal. In that game, he became the first player to score on two direct free kicks in a match after coming on as a substitute. He recorded one assist in a victory against LAFC on Apr. 7. US Open Cup: Started both of Atlanta United’s Open Cup matches. Played a full 90 minutes against Charleston in the Fourth Round, while going 62 minutes against Chicago Fire in the Round of 16. USL: Kratz made his ATL UTD 2 debut on June 16 against Ottawa Fury FC. He went on to make two starts in ATL UTD 2’s inaugural season.
2017 (Atlanta United): Kratz made 20 appearances and five starts, recording one goal and one assist. His free kick masterpiece in a 7-0 victory over New England on Sept. 13 was voted MLS Goal of the Week. Recorded an assist in 3-1 win against Columbus on June 17. US Open Cup: Started, played 90 minutes and scored in 3-2 win over Charleston Battery on June 14. Started, played 90 minutes and recorded an assist in 3-2 loss to Miami FC on June 28.
2016 (Philadelphia Union): Philadelphia signed Kratz ahead of the roster freeze deadline Sept. 15. He did not make an appearance.
2015/2016 (SV Sandhausen): Kratz began the season with two assists in the first three games. He injured his foot in early October and missed the rest of the season.
2014/2015 (SV Sandhausen): Kratz transferred to SV Sandhausen June 30, 2014. He appeared in 15 matches after injuries kept him out of play for most of the first half of the season.
2013/2014 (Eintracht Braunschweig): In his first season in Bundesliga, and Braunschweig’s first in 28 years, Kratz scored against Borussia Dortmund (Aug. 18) in the second game of the season. Kratz suffered a number of injuries and appeared in 14 games, starting in 12. Braunschweig finished last in the league and was relegated to 2. Bundesliga.
2012/2013 (Eintracht Braunschweig): Following Aachen’s relegation, Kratz transferred to Eintracht Braunschweig and remained in 2. Bundesliga. He started his first campaign with Braunschweig with five assists in his first nine games before he suffered another high ankle injury which kept him sidelined for four months. He returned to play in nine games to finish the season. Kratz scored a brace against VfB Lubeck (Aug. 17) in a first round matchup for the DFB-Pokal cup. Braunschweig earned promotion to Bundesliga after finishing second in the table.
2011/2012 (Alemannia Aachen): In 25 matches Kratz started in 17, recording one assist. Alemannia Aachen suffered relegation to 3. Liga after finishing in the bottom two.
2010/2011 (Alemannia Aachen): Kratz appeared in 31 league games, starting 30 and scoring two goals with three assists.
2009/2010 (Alemannia Aachen): Kratz signed with 2. Bundesliga club Alemmania Aachen August 5, 2009. He made his debut against 1. FC Kaiserslautern (Aug. 23) as a substitute. Kratz scored his first goal against TSV 1860 Munich (Feb. 20) in a 2-3 loss. He recorded an assist on consecutive games against MSV Duisburg (Dec. 18) and Karlsruher SC (Jan. 15). Kratz suffered a high ankle injury which kept him out of action for the remainder of the season.
2006-2009 (Bayer 04 Leverkusen II): Kratz appeared in 90 matches across all competitions scoring 11 goals.