The 35-year-old has failed to recover from the ankle injury he sustained in the 2-2 draw against Swansea City in Matchweek 4.
"Terry is working hard but he didn't recover for the game against Arsenal," Conte told chelseafc.com. "I don't know when he will play because it is important what the player feels, and the pain he feels."
Olivier Giroud (toe) faces a late fitness test, while Aaron Ramsey (thigh) has been ruled out altogether, as Arsene Wenger’s charges bid for their first victory over Chelsea since a 5-3 win at Stamford Bridge in October 2011.
"We have no new injuries," Wenger told arsenal.com. "Giroud has a test to see if he can be involved, he had a good training session [on Thursday] so he is really the only one who could come back."
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