Viduka has not kicked a ball in anger this season because of the Achilles problem he suffered late last season.

And Viduka – 33 today – could now need an operation on the long-standing injury.

Viduka – who it had been hoped would miss just a handful of games at the start of the campaign – has travelled to his native Australia for a second opinion, and interim manager Joe Kinnear admits all he can do is hope for the best.

"Mark Viduka has had one scan on his injury, but he wanted a second opinion, and so too did our medical people, and that's why he has gone back to Australia," said Kinnear.

"However, we know there's a chance that Viduka may need surgery, and if this turns out to be the case then we'll be without his services for a minimum of six months, and this isn't good news.

"We'll know more when Viduka comes back in about six days, and in the meantime all we can do is wait and hope."

Back in May, when news of the injury broke, an operation was a possibility. However, it was felt at the time that an injection, and three months' rest, would see him recover.

Viduka – who was restricted to just 21 starts by injury last term – is now facing up to missing almost all of his second season at Newcastle.

His fellow striker Obafemi Martins is also on the injured list with a knee problem, and the 23-year-old is expected back next month.

Kinnear said: "He had good contacts in his days with Inter Milan, and he's been to Italy for a scan on his knee injury.

"But his situation hasn't really changed, and the initial six weeks' forecast of how long he'll be out looks about right."