French heavyweight Tony Yoka has withdrawn from his bout against Russia's Murat Gassiev, which was scheduled for July 11th in Moscow for Gassiev's WBA regular title. The move was caused by an injury to Yoka, according to reports by journalist Dan Rafael and L’Équipe. Yoka is on a run of very bad luck -- this latest setback follows the cancellation of his previous scheduled bout—set for April 25th in Paris against Britain's Lawrence Okolie, who was at the time WBC #1 contender. Okolie tested positive in a doping test four days before the fight. Yoka had been on a four-fight winning streak prior to that. Reports are that Gassiev is looking for a replacement opponent,