Ivan Klasnic is to sue two doctors at Bundesliga club Werder Bremen over his treatment for kidney problems that eventually led to two organ transplants, the Spiegel magazine reported.
Klasnic, who joined French side Nantes this season, underwent two kidney transplant operations in early 2007 while still at Bremen and claims negligent treatment and mistakes on the part of the club's medical team. The doctors reject the allegations, dpa reported.
According to the report, made available ahead of Monday's publication, attempts in the previous nine months at an out-of-court settlement have failed.
The 28-year-old striker is now looking for 2 million euros (2.6 million dollars) in compensation with the case due to be heard in a Bremen court on April 17.
Croatian international Klasnic scored 49 league goals for Bremen between 2001 and 2007 for Bremen as well as netting 20 times in the Champions League.