The unfancied Swiss scored a 1-0 victory over eventual world champions Spain in a Group H opener in Durban last June and Bilek told a news conference on Thursday that his side were capable of causing another upset in Granada.
"They (Spain) have suffered some defeats recently and they have weaknesses," said the Czech coach.
"The Swiss knew how to defend, scored a goal and won the match. That can happen tomorrow."
Spain's form since their first World Cup triumph in South Africa has been patchy and they lost friendlies to Argentina and Portugal in September and November respectively.
They also had a scare in October's Euro 2012 qualifier against Scotland in Glasgow, surrendering a two-goal lead before snatching a 3-2 win thanks to a late Fernando Llorente strike.
Bilek included newcomers Libor Kozak and Tomas Vaclik in his squad for Friday's match and the qualifier at home to Liechtenstein on Tuesday as the Czechs aim to bounce back from a 4-2 friendly defeat by Croatia last month.
Arsenal midfielder Tomas Rosicky has a chance to avenge last month's Champions League defeat by Barcelona who have six players in the Spain squad.
"I can't say it's extra motivation for me," said Rosicky. "It is a huge game for us, for the whole team.
"Spain are the favourites, no doubt about that, but we didn't come here to lose and we will fight."
