Djokovic out of Davis Cup with sore knee

By the Associated Press | July 8, 2011 | 9:29 AM EDT

Sweden's Ervin Eleskovic, left, and Serbia's Novak Djokovic are seen in Halmstad, Sweden, Thursday, July 7, 2011, after the draw for the Davis Cup quarterfinal between Sweden and Serbia at the Halmstad Arena, starting Friday. (AP Photo/Scanpix Sweden, Maja Suslin) SWEDEN OUT

HALMSTAD, Sweden (AP) — Top-ranked Novak Djokovic has withdrawn because of a left knee injury from his singles match for Serbia against Sweden in the Davis Cup quarterfinals.

The Wimbledon champion will be replaced by Janko Tipsarevic, who will face Ervin Eleskovic. Sweden's Michael Ryderstedt will play Viktor Troicki in the opening match on Friday.

It was unclear whether Djokovic would be back for the reverse singles on Sunday.