Berlin, June 20 (IANS): German football club Cologne striker Patrick Helmes has announced his retirement due to a persistent hip injury.

The former German international confirmed in an official statement on Friday. After many setback and injuries Helmes retires from professional football after ten years. He will however stay with Cologne to assist Under-21 head coach Martin Heck, reports Xinhua.

"I am looking forward to this task, aside from that, I am happy to remain in Cologne," Helmes told the club's official homepage.

The 31-year-old was trapped in an injury crisis since 2006 when he fractured his leg. In addition, his ruptured his cruciate ligaments twice before an persistent cartilage damage in his hip made a comeback on the pitch impossible.

"I had a wonderful time as a professional. I tried very had to return to the pitch after my injuries but my body doesn't allow a comeback. Now it' s time for a reorientation," Helmes said.

The former German international, who scored twice in 13 caps, started his professional career in 2005 in Cologne. Helmes scored overall 45 goals in 98 Bundesliga appearances. He also played for Leverkusen and Wolfsburg.