By dpa correspondents

Berlin (dpa) - Werder Bremen have fears over Claudio Pizarro ahead of
Saturday's Bundesliga match at Borussia Dortmund after the Peruvian
forward hurt his back on international duty Tuesday.

"In the 49th minute of his 1-0 defeat to Uruguay, Pizarro had to be
substituted through injury," Bremen said Wednesday.

"The Werder goalscorer was suffering back problems but an exact
diagnosis is still to be made."

The 37-year-old Pizarro is Bremen's top scorer with 12 goals as the
side fight against relegation from the top flight. Earlier this
season he matched Marco Bode's all-time record of 101 goals for the
club.

"Towards the end of the first half I felt a twinge in my back. I
tried to play on in the second half but I still felt it so it was
better to go off and let somebody who was fully fit play," Pizarro
was quoted as saying.

Pizarro is scheduled to arrive back in Bremen late Thursday where he
will meet with the team doctor.