The Newcastle frontman has not played all season and many at Newcastle feared his injury could be career threatening.

However, Newcastle assistant manager Chris Hughton told The Daily Mail: “It is a great boost. This was his first day training and it was good to see him back.

"As regards to putting a Newcastle United shirt back on we are not sure about a timescale. Hopefully it will be over the next few weeks.

“The difficulty is he has been out a while but he has had no setbacks in his rehabilitation which has gone very well and as long as that continues he could be involved in the next few weeks.”

Viduka, who has scored 11 goals in 43 internationals, joined up with the Socceroos squad last month and at the time vowed to return to the international fold.

"Of course I want to play for Australia again - it's something that's never out of my mind," said Viduka, who has not played for Australia since July last year.

"I've got to be 100 per cent fit and 100 per cent sure in my mind that my heel is strong enough. When that happens, I'll be back for Australia."