Viduka has been playing with an Achilles injury with speculation he could require surgery during the summer.
Verbeek, who has received assurances from the player that he wants to continue his international career in the run-up to the 2010 finals in South Africa, admitted he would be a huge loss.
Verbeek: "Nobody can do the same as Mark Viduka. I have seen enough games in England and Europe - he is special.
"You don't see players like him very often. He is so important for the team he is playing at.
"We don't have players like that. With all respect for Scott (McDonald), Josh (Kennedy), Archie Thompson and John Aloisi, if we can use him, we will use him; if he is ready, he will come.
"We have some players who can do a great job also, but if we get a chance to use Mark, we will do it."