Playmaker Rosicky's precise passing and ability to raise the game's tempo helped the Czechs take an early two-goal lead against Greece on Tuesday but he had to come off at half-time.
"We will see tomorrow," Bilek said of Rosicky, who missed the Czechs final two warm-up games with a calf injury.
"It was his Achilles heel but we hope he is fit for the third match because he is our key player."
The Czechs were a different team in the second half without their skipper and failed to exert the pressure that saw them score twice in the first six minutes before hanging on to win.
Bilek also bemoaned Petr Cech's blunder that led to the Greek goal but said his team responded the way he wanted after a crushing 4-1 defeat by the Russians in their opener.
"There is not one player on the team I would not praise," Bilek said. "We wanted to attack even more but it was difficult when Rosicky left."
The Czechs brought in Tomas Hubschman as a defensive midfielder for Petr Jiracek who moved to the right wing - a decision that paid off almost immediately as the pair combined for the first goal.
Bilek said his decision to modify the lineup was an attempt to hold more possession than the team did against the Russians and to play tighter in defence.
"In this match we wanted to close the defence," Bilek said. "That is why Jiracek played in a position that is not usual for him. He performed very well and was making runs along the line and really getting in to the game."