The Middlesbrough and Australia striker has said that a combination of family reasons and concerns over frequent long-distance travel could prompt him to quit the Socceroos later this year.
“I have one kid and a second one on the way,” Viduka said.
“I miss my family when I have to go away.”
Australia are switching from the Oceania region to Asia from this year, and will take part in the Asian Cup qualifiers after the World Cup. That will only increase the already extensive travel requirements for English-based players, and Viduka believes it could be too much for his ageing body.
“For players from Europe, they only have a three or four-hour flight, but I have to travel to the other side of the world. It takes a week to recover.
“There will be a lot of games with the Asian Cup and I might be away every month. I have to think of the pros and cons.
“I am thinking about my future with the national team and the results at this World Cup could be very important to that.”
The 30-year-old has played 32 times for his country, scoring six goals.
Meanwhile, Ivory Coast midfielder Didier Zokora “is very, very interested” in moving to Tottenham, according to the player’s agent.
The 25-year-old is expected to be a key player for the Elephants at the World Cup in Germany, and the St Etienne star has been watched several times by Spurs sporting director Damien Comolli, who himself used to be the technical director of the French club.
Zokora’s agent Franck Belhassen said: “I know Tottenham are interested. I know they’ve already spoken with St Etienne and have made their first bid.
“But for the moment nothing is done. What is certain is that Damien Comolli knows Didier very, very well. And Didi is very, very interested in moving to Tottenham.”