The 23-year-old is unlikely to start after doing his first training session on Friday after a period out with illness.
Mauricio Pochettino has also explained that, despite playing Premier League opposition in the Summer Series, he will continue to use his young players on Saturday night.
Chelsea are expected to use a similar group of players to the one who beat Wrexham 5-0 in North Carolina on Wednesday night.
Bashir Humphreys and either Ben Chilwell or Marc Cucurella will complete the backline. Chelsea will also play with a young midfield again after Andrey Santos, Carney Chukwuemeka and Cesare Casadei all excelled last time out.
Predicted Chelsea XI: Kepa; Gusto, Thiago Silva, Humphreys, Chilwell; Andrey, Chukwuemeka, Casadei; Jackson, Nkunku, Sterling.
Injured: None
Doubt: Chalobah
Time and date: 12am BST on Sunday, July 23, 2023
Location: Lincoln Financial Field, Philadelphia