Jeff Gordon comes out of NASCAR retirement to replace Dale Earnhardt Jr

Earnhardt pulled out of last weekend's New Hampshire Motor Speedway round having suffered concussion-like symptoms during the build-up.

Though Alex Bowman filled in for him at the Loudon track, Hendrick management revealed last week that the longer-term plan if Earnhardt remained sidelined was to bring Gordon out of retirement.

Four-time Cup series champion Gordon stepped down from driving at the end of the 2015 season, but he has remained involved with NASCAR in a television commentary role.

He will make his competition return at Indianapolis this weekend - where he has won five times - and stay on for at least the following week's Pocono round.

Team owner Rick Hendrick said: "It's going to be an emotional weekend with Dale not being there and seeing Jeff back behind the wheel.

"Jeff's a team player. I know he'll be ready, and I know Dale has incredible trust in him."

Earnhardt missed two races in 2012 with concussion and sought neurologists' advice earlier this month when he suspected symptoms initially believed to be an allergy or virus were potentially concussion-related.

He believes the problems might have been caused by crashes in the recent Michigan and Daytona races.

Hendrick emphasised that the team still fully expected Earnhardt to return.

"Our focus is giving Dale all the time he needs to recover," he asid.

"There's nothing we want more than to see him back in the racecar, but we'll continue to listen to the doctors and follow their lead.

"What's best for Dale is what's best for Hendrick Motorsports and everyone involved with the team.

"We're all proud of him and looking forward to having him racing soon."

Earnhardt has yet to win a race this year and slipped to 15th in the championship while absent from New Hampshire.

That means he is the last driver currently holding a Chase place on the basis of championship position, with Trevor Bayne, Ryan Blaney, Kasey Kahne and Kyle Larson all within 25 points of him in the standings going into the Brickyard 400 at Indy.