Dale Earnhardt Jr.'s race team said on Twitter that four-time Sprint Cup champion Jeff Gordon won't be able to drive the No. 88 car next week in Michigan.
Earnhardt has missed the past four races and will sit out the Saturday night event at Bristol Motor Speedway as he recovers from a concussion. Gordon has filled in the last three races and will start 11th Saturday in the Hendrick Motorsports entry.
The race team's Twitter feed said Alex Bowman, who drove the car in New Hampshire last month, would return to the driver's seat if Earnhardt is not cleared to race.
Earnhardt is scheduled for a medical check and a decision on his status is expected early next week.