Germany captain Michael Ballack looks almost certain to miss his country's opening World Cup clash with Costa Rica after pulling out of Wednesday's practice session.
The 29-year-old had not trained since picking up a right calf strain in last Friday's 3-0 friendly victory over Colombia.
He returned on Wednesday but was forced to end the session early after his injury would not allow him to participate in the final training match.
The German Football Association announced Ballack will 'receive intensive medical treatment in the next few hours', but head coach Jurgen Klinsmann has previously insisted he will not play anyone 'who is not fit 48 hours before a match.'
And with Werder Bremen midfielder Tim Borowski performing well as of late, it appears Klinsmann will be resting his skipper in Friday's curtain-raiser to give him enough time to recover.
