Red Bull Racing says their driver was released Friday night from a Washington hospital. He was admitted Wednesday.
Red Bull Racing says Vickers' return to racing is uncertain. He will not race this weekend at Dover International Speedway.
The 26-year-old Vickers has been cleared to fly to Charlotte, N.C., where he will meet with a group of specialists.
Casey Mears will replace Vickers in the No. 83 Toyota.