Russia, semi-finalists at UEFA Euro 2008, are the overwhelming favourites to reach the finals in South Africa next summer, but Hiddink insists that unheralded Slovenia can rise to the occasion. "We should never underestimate Slovenia," Hiddink said. "They are a very strong team, both in terms of their results and playing style.
"Slovenia are very disciplined and hard-working with a modern concept of playing. Their strength is their unity, there are no individual stars in their line-up."
Dutchman Hiddink added that the outcome of the two-legged play-off with Slovenia will have an effect upon the development of Russian football. "Two very important matches lie ahead," he said.
Russia skipper Andrei Arshavin confirmed Hiddink's beliefs. "In the play-offs any accidental goal can change the situation completely," said Arsenal star Arshavin.
"It's even more important as we still do not know exactly what we are capable of. We should avoid any kind of celebration before we achieve our goal."
Russia, who finished second in their group four points behind Germany, have met Slovenia on three previous occasions - clinching a win in a friendly while two of their meetings in the 2002 FIFA World Cup qualifying campaign ended in a draw and a defeat.
Russia have played twice previously appeared in play-offs. In their first attempt, they lost their two-legged clash for a place in the 1998 FIFA World Cup finals to Italy. The second try was more successful with Russian beating Wales on their way to the UEFA Euro 2004.
On Saturday, Russia should be at full-strength, but Hiddink is concerned about the poor form of Tottenham striker Roman Pavlyuchenko, who is lacking match practice at his club. Another first-team player, Chelsea winger Yury Zhirkov, who recently overcame a knee injury, is also lacking match fitness.
Slovenia manager Matjaz Kek confidently predicted his team would win in Moscow. "We are definitely capable," said Kek. "The Russians are under pressure as favourites and we have a very strong desire to play at our first ever World Cup."
Slovenia skipper Robert Koren warned Russia they should prepare for a shock. "We have already proved that we can play quality football," Koren said. "But we have continued improving our playing. We will give everything we have to win."