Career
Early Bartels began his career at Turn- und Sportverein Russee and later played for SpVgg Eidertal Molfsee before joining Holstein Kiel in 2002. In 2005 Bartels moved up to Holstein Kiel World War II Later that year he broke into the first team squad at Kiel, before joining Hansa Rostock of the Bundesliga in 2007. Rostock
Bartels made his debut for Rostock against VfL Wolfsburg in a 3–1 defeat.
He then scored his first Bundesliga goal with a bicycle kick on 1 March 2008 against Arminia Bielefeld to tie the game late on.
Football Club Saint Pauli
Bartels became an instant regular at Saint Pauli, making 31 appearances in his debut season. His first start came on Matchday 6, against Borussia Dortmund.
However, the club was relegated from the Bundesliga having finished in last place. His strongest two seasons for Saint Pauli were the 2012-2013 season and 2013-2014 season, in both of which he scored 7 league goals in the 2.
Bundesliga. Werder Bremen
Bartels joined Werder Bremen from Football Club Saint Pauli for the 2014-2015 Bundesliga season.
From Matchday 3 he was able to command a regular place in the team and made 29 league appearances. As of Matchday 25, he has appeared 24 times for Bremen in the 2015-2016 season, mostly on the right of the midfield.
