opening game of the season, setting up a goal in a 2–1 loss against Borussia Mönchengladbach. Derdiyok would struggle to score his first goal until matchday 11 (on 18 November 2012) in a 3–1 loss against Wolfsburg. However, his poor performance at Hoffenheim was criticised that Markus Babbel regretted signing him and Tim Wiese. Following this, Derdiyok's playing time was soon reduced. Derdiyok would also be demoted to the reserve side because his higher wages were affecting the club's finance and he was no longer included in the first team under manager Markus Gisdol. Then, Derdiyok suffered an abdominal problems, which ruled him out for the 2012–13 season. Derdiyok quoted admitting about his move: "We have to be ashamed of us, especially me. We cannot play the remaining games in such a way. I earn my bread here, I have to give something in return." After one season with Hoffenheim, Derdiyok was among nine players to be left out for the club's training camp ahead of the 2013–14 season. Derdiyok told Sport1 in an interview, quoting: "We have all disappointed. It can not be that I'm the bogeyman. Things were promised to him, "have not been complied with at the end. There has been much done wrong." After being told by Switzerland's manager Ottmar Hitzfeld to leave as soon as possible. Derdiyok found himself being linked with Hamburg. Derdiyok was sent to the club's reserve side by Manager Gisdol. Return to Bayer Leverkusen (loan) On 30 August 2013, Derdiyok returned to Bayer Leverkusen on a season long loan until the end of the 2013–14 season. Upon his loan move, Derdiyok vowed: "I will be as strong as never before!" However, Derdiyok featured less and only appeared on the bench instead. Manager Sami Hyypiä quoted on Derdiyok about his recent attitude: "Eren must focus even more, then he is a very good player. He has quality. We all need to help him get this quality." After the end of the 2013–14 season, Derdiyok's loan spell with the club came to an end and he returned to Hoffenheim. Kasımpaşa A few days after the end of Bundesliga season, Derdiyok left Hoffenheim to join Süper Lig Turkish side Kasımpaşa ahead of a new season. Derdiyok cited moving to Turkey as "target and ideal" Derdiyok would spend the next three seasons at the Istanbul club. Galatasaray Derdiyok signed a three-year contract with Turkish club