The defense has yet to play this season, while the youthful midfielder was nearing a comeback.
Carney Chukwuemeka and Trevoh Chalobah have both been sidelined with injuries, according to Chelsea.
The teenage midfielder had knee problems after rejoining full first-team training after missing several weeks, Standard Sport reported earlier on Wednesday.
Chalobah’s setback has not yet been further explained by Chelsea, although the defender has missed the entire season due to a thigh ailment.
A statement said: “Defender Trevoh Chalobah and midfielder Carney Chukwuemeka have both suffered recent setbacks in their bid to return from respective injuries sustained earlier this season.”Before continuing their recuperation at Cobham with the club’s medical team, the pair will now be subject to more scrutiny.
Reece James has reportedly further delayed his efforts to return to match action after suffering a knee injury that has kept him out of action since the second game of the season.
Ahead of the crucial London derby against Arsenal on Saturday, Chelsea has not released an update on its captain.