Bayern Munich midfielder Hamit Altintop has been ruled out for several weeks because of complications with the foot injury he suffered in March.
The Turkish international broke his right foot in an international friendly against Belarus on March 26.
He has since had a metal plate inserted, but has now suffered a setback in his bid to regain full fitness.
A statement on the club's official website read: 'Hamit Altintop will be missing for several weeks. The midfielder is still suffering from problems in his right foot.
'FC Bayern's medical department has now diagnosed a stress reaction of the bone.'
Altintop played in Bayern's 1-1 draw at Borussia Dortmund on Saturday, but was taken off late in the game.