Newcastle boss Glenn Roeder has admitted injured striker Michael Owen may not play at all this season.
Owen collapsed against Sweden
Owen, 26, ruptured his anterior cruciate knee ligament in England's 2-2 draw against Sweden at the World Cup finals and is set to have an operation.
"It's a long term injury. I don't know if he'll play again this season," Roeder told BBC Radio Newcastle.
"He's getting the best possible treatment and will have the best surgeon in the world operating on him."
Roeder added: "Michael has an injury that will take a fair bit of time to repair. If we put a date on it and we say that he'll be back by next March, and then he's not fit, then it will cause more problems."
Owen's cruciate ligament surgery had been delayed until September because he required an operation to repair cartilage damage on his injured right knee in July.
The England international, who signed for Newcastle from Real Madrid for £17m in August 2005, missed most of the second half of the 2005-06 season with a broken foot.