That is according to manager Jose Mourinho, who watched on as two of his key players suffered injury blows in Tuesday's 0-0 draw with Atletico Madrid in the Champions League semi-final first leg.
Goalkeeper Cech was withdrawn in the 18th minute after falling on his right side following an aerial duel and sustaining a suspected dislocated shoulder.
Terry, meanwhile, twisted his left ankle and was substituted with 17 minutes to go at Vicente Calderon as Chelsea were left to count the cost of the stalemate.
The double injury setback comes as a huge blow for Mourinho and his men, who face leaders Liverpool in a potential Premier League title decider at Anfield on Sunday before the return leg against Atletico at Stamford Bridge three days later.
"Petr Cech's season is over," confirmed the Portuguese. "For John, we will have to play the final for him to play again.
"It wasn't the result I wanted before kick-off, but I didn't want to start the second leg a goal down either.
"A goalless draw is not a positive result for a team playing the second leg at home, but it'll do.
"Atletico were frustrated, whereas usually they are the ones who frustrate other teams.
"My side had a solid performance, we played in a way that irritated them."
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