The Czech Republic goalkeeper was forced off the ground at the Vicente Calderon in the 18th minute after he was knocked heavily to the ground as he punched the ball from underneath his own crossbar.
The Blues medical raced to Cech before bringing him off, wrapped in a red blanket, with Australian gloveman Mark Schwarzer his replacement.
"Petr Cech's season over. Don't ask me technically, but season over," said Mourinho.
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