Gary Cahill says Chelsea need to avoid "too many injuries" as questions were asked about the depth of their squad.
Antonio Conte named 24 players in the squad for the Community Shield defeat by Arsenal and four of the seven substitutes were academy players.
The Premier League champions have signed four players but Conte has said he would like to strengthen further.
Asked if the Chelsea squad was small, club captain Cahill replied: "The back of the programme was interesting."
The England defender was referring to the squad lists on the back of the match programme - which showed 24 Chelsea players compared to 41 from Arsenal.
Cahill added: "In terms of quality we've certainly got that and you just have to hope we don't have too many injuries."
Chelsea have bought Alvaro Morata, Tiemoue Bakayoko, Willy Caballero and Antonio Rudiger this summer for a combined £129m.
But they have sold Nemanja Matic, Nathan Ake, Asmir Begovic, Bertrand Traore, Christian Atsu, Nathaniel Chalobah and loaned out Tammy Abraham, Nathaniel Chalobah, and Ruben Loftus-Cheek.
Striker Diego Costa, who scored 20 goals last season, has been told he does not have a future at the club.
Former Chelsea striker Chris Sutton has said their squad looks "bare", adding: "They need more and I don't think Conte is happy."
Conte issued terse responses to questions after the penalty shootout defeat on Sunday and declined to answer when asked if his squad was ready to challenge in all four competitions this season.
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