The announcement guarantees that he'll miss the race at New Hampshire Motor Speedway on Sunday, where Alex Bowman will stand in for Earnhardt.
Gordon, now an analyst for Fox Sports, retired last year after 23 years of racing.
The victor of the first Brickyard 400 in 1994, Gordon has won a record five Sprint Cup races at Indianapolis - 1994, 1998, 2001, 2004 and 2014. He raced last Saturday night in the Quaker State 400 at Kentucky Speedway but the symptoms persisted after the race.
On the plus side, Jeff Gordon fans will get to see their favorite driver back in action on a track where he's had a ton of success, and in a vehicle that is one of the most popular on the circuit.
Hendrick Motorsports held a press conference on Friday to discuss Dale Earnhardt Jr. and where everything now stands with the driver of the No. 88 machine. "And at that time, it was in the contingency that he would have to backfill for Dale after Dale started the race".
Duchardt described Gordon as "not a bad person to think about to put in the vehicle. (Thursday) around noon is when I found out that Dale could not be in the vehicle for this weekend, based on their suggestion". He's got as much experience as possible and likely has a legitimate shot at winning it, even if he has sat out for the season thus far.
Duchardt said Hendrick could wait until Wednesday next week to decide whether Earnhardt or Gordon would race at Indianapolis and has not planned beyond that. Obviously I'm hoping Dale feels better, but at the same time, it's the best opportunity I've ever had in my life.
"Additionally, NASCAR's medical advisory group, a team of consulting physicians who work directly with the league on policy development while regularly meeting with drivers to continue the education process, includes many leaders in the neurological field". "I saw a family doctor and was given medication for allergies and a sinus infection". When that didn't help, I made a decision to dig a little deeper.
"I think we just want to take it one race at a time", Duchardt said.
SPRINT CUPNEW HAMPSHIRE 301Site: Loudon, New Hampshire Schedule: Friday, practice (NBCSN, 11:30 p.m.), qualifying (NBCSN, 4:45 p.m.); Saturday, practice (CNBC, 10 a.m.), practice (NBCSN, 12:30 p.m.); Sunday, race, 1:30 p.m., NBCSN.
It could end up being a moot point if Earnhardt is cleared to return by the middle of next week.