Red Bull Racing says the 26-year-old is "progressing well" after being hospitalized in Washington last week. Vickers has been meeting with specialists and his physician since returning to Charlotte.
Vickers is still undergoing evaluation. Red Bull says Vickers remains in good spirits, though his return to racing is uncertain.
Vickers and Red Bull Racing general manager Jay Frye will address the situation Friday at Charlotte Motor Speedway.
Casey Mears served as Vickers' replacement in last weekend's race at Dover, finishing 22nd.