Also, Carney Chukwuemeka, Ben Chilwell, Armando Broja, Trevoh Chalobah, and Wesley Fofana are all out.

Source: https://www.completesports.com/chelsea-suffer-double-injury-blow/

Experienced defender Thiago Silva could be handed his first start in pre-season but Trevoh Chalobah is a doubt with an Achilles issue.

Source: https://www.sussexexpress.co.uk/sport/football/brighton-and-hove-albion/chelsea-v-brighton-live-confirmed-team-news-and-stream-details-from-philadelphia-4228536

Midfielder Chalobah was included in the starting XI for the first time since the opening day of the season at Blackburn.

Source: https://www.birminghammail.co.uk/sport/football/football-news/what-carlos-corberan-nathaniel-chalobah-27958144

Reece James, Armando Broja, Wesley Fofana, Marcus Bettinelli, Trevoh Chalobah and Benoit Badiashile are also out.

Source: https://www.express.co.uk/sport/football/1805852/FPL-injury-news-Man-Utd-Chelsea-Arsenal-Gabriel-Jesus

Smalling only has three appearances this term but the possible additions of Sarr and Chalobah could suit the out-of-favour Chelsea duo - especially in a three-man defence.

Source: https://www.thesun.co.uk/sport/24778843/roma-mourinho-transfer-chelsea-pochettino-chalobah-sarr/