England striker Michael Owen underwent an operation on Tuesday to insert a metal pin on his broken foot.
Owen had the operation at a hospital in Manchester and Newcastle manager Graeme Souness expects to be without his striker for up to 10 weeks.
The 26-year-old cracked the fifth metatarsal of his right foot during Saturday's 2-0 defeat at Tottenham.
Owen's injury added to Newcastle's lengthy absent list, which includes Scott Parker, Shola Ameobi and Emre.
Kieron Dyer, Steven Taylor, Stephen Carr and Craig Moore are also out injured, while Lee Bowyer is suspended for another two games.
Prior to undergoing the operation Owen told The Times: "I have been given the name of a good surgeon and I am going to have a pin inserted.
"It's not essential but I've been told that it should give me the best chance of a quick recovery."
Owen is not only hopeful of being fit for the World Cup Finals in Germany, which start in June, but also optimistic of his chances of playing for Newcastle again this campaign.
"I don't need any miracles to be playing again this season and, fingers crossed, I will see at least a month of the Barclays Premiership season as well as the World Cup," said the former Real Madrid and Liverpool frontman.
Owen related his injury to similar ones suffered by England team-mates, David Beckham, Steven Gerrard, Wayne Rooney, Gary Neville and Ashley Cole.
"The experiences of so many of my colleagues provides some reassurance that I should back in two to three months," he said.
"Some players with broken metatarsals have been back on the pitch in eight weeks so that is the most optimistic scenario.
"Thirteen weeks seems to be the worst case to judge from the information I have had from the likes of Gerrard."
Owen, bought from Real Madrid for £17m in August, has been an instant hit alongside captain Alan Shearer up front, scoring seven goals in nine starts.
England coach Sven-Goran Eriksson said he would be monitoring Owen's recovery closely ahead of the World Cup.
"Obviously I'm very disappointed for Michael," Eriksson told the Football Association website. "It's very bad luck for him and for Newcastle United.
"Michael is a fantastic striker and a very important player for his club and for England.
"I hope that he returns to fitness as soon as possible and I will follow his progress very closely."