Mohamed Zidan picked up a foot injury during training with Borussia Dortmund, the Bundesliga club said. Dortmund's official site stated that the Egypt forward failed to take part in Wednesday's training and was taken to hospital to undergo tests. The league leaders have yet to determine the extent of the problem, or the period for which the striker will be out for. Zidan has yet to play a single game for Dortmund this season as he just returned for a six-month layoff, following a cruciate knee ligament surgery in April. The 28-year-old, however, played for Egypt in last week's friendly with Australia, scoring from the spot in the 3-0 victory. Earlier this month, Dortmund manager Juergen Klopp said that Zidan is match fit, but conceded that he prefers to be patient with the Egyptian.