— Hendrick Motorsports says Dale Earnhardt Jr. will retire at the end of this season.Earnhardt is a 14-time winner of NASCAR's most popular driver award. He has 26 career Cup victories, and that includes a pair of wins in the Daytona 500.Earnhardt is a two-time champion in NASCAR's second-tier series. But the son of the late seven-time champion has never won a Cup title.Earnhardt turns 43 in October, was married during the offseason and has stated he wants a family.He's also been plagued by concussions and missed half of last season after suffering yet another one. He's become an advocate for research of sports-related brain injuries.