Cech will be replaced by David Ospina, who played in the 2-1 defeat to Dinamo Zagreb.
Aaron Ramsey could also drop out of the team that beat Leicester 5-2 on Saturday, along with Per Mertesacker and Mathieu Flamini.
Gabriel is set to come into the team as well as Francis Coquelin and Alex Oxlade-Chamberlain.
Manager Arsene Wenger, whose side face Manchester United in the Premier League on Sunday, insists his selection is not being influenced by the game against their rivals.
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Petr Cech is set to drop to the bench against Olympiacos
The Gunners are desperate to get off the mark after a slow start to life in Group F.
"Some players had two tough games at Tottenham and at Leicester where they were a high level physically," Wenger said.
"I will have to analyse that and make my decisions."
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David Ospina will replace Cech in the Arsenal goal
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He also insists the decision to bring in Ospina is no reflection summer signing Cech.
The star stopper signed from Chelsea for £10million but Wenger is keen to give his second choice some game-time.
"This is not just because I have decided Ospina plays in the Champions League," he added. "It will go game by game and there can be a different decision.
"I need to give him games. He is a top-level goalkeeper. It is of course harsh that he is on the bench.
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Arsene Wenger, pictured with former player Robert Pires, says his selection has not been influenced
