Dale Earnhardt Jr. retired after 18 seasons in NASCAR on his own terms following a number of concussions received in racing, including one that sidelined him for the final 18 races of the 2016 season.

NASCAR's perennial most popular driver struggled with his balance and vision for weeks in 2016, stemming from a crash at Michigan in June that forced Earnhardt to seek medical attention and quit racing under doctors' orders at New Hampshire nearly four weeks later. 

Earnhardt told team owner Rick Hendrick last March he intended to retire after the season. His contract with Hendrick Motorsports was set to expire after 2017, but most had expected the 43-year-old driver to re-sign and continue racing.

Earnhardt first endured a concussion in the Fontana race in April 2002 but did not disclose the injury until September while continuing to race. Ten years later, Earnhardt sustained two concussions in six weeks. He self-diagnosed one at a tire test in Kansas and then he suffered another after a big crash at Talladega. Afterward, he voluntarily went to a doctor for an evaluation and had to sit out two Chase races in October because of his condition. 

Junior said during an emotional retirement press conference last year he plans to race two Xfinity Series races in 2018 with the team he owns. He will join NBC as a NASCAR broadcaster later this season.

Who replaced Dale Earnhardt Jr. in NASCAR?

Alex Bowman has replaced Earnhardt at Hendrick Motorsports in the No. 88 Chevrolet. Bowman was Earnhardt’s replacement driver in 2016, recording three top-10 finishes in 10 starts with a 19.7 average finish. Bowman, who is on the pole for the Daytona 500, is just 24.

How many NASCAR wins does Dale Earnhardt Jr. have?

Earnhardt made his first career Cup Series start on May 30, 1999, at Charlotte Motor Speedway. Since then, the Kannapolis, N.C., native has 26 Cup Series wins, which include four wins at Daytona and six at Talladega, Earnhardt has 24 Xfinity Series wins and back-to-back titles in the Busch Series (now the Xfinity Series).

A 15-time most popular driver award recipient, Earnhardt is a two-time Daytona 500 winner.