Dale Earnhardt, Jr.

Dale Earnhardt Jr., driver of the #88 National Guard Chevrolet, looks on during practice for the NASCAR Sprint Cup Series AdvoCare 500 at Phoenix International Raceway on Nov. 9, 2013. (Todd Warshaw / Getty Images)

NASCAR's Dale Earnhardt Jr. on Friday acknowledged he was concerned about who might replace his crew chief Steve Letarte after Letarte leaves at the end of this season.

"It's a guy that's going to be hard to replace," Earnhardt told reporters ahead of a Sprint Cup Series test session at Florida's Daytona International Speedway, site of the season-opening Daytona 500 on Feb. 23.

But Earnhardt added that "I feel confident that we can continue to see success."

Letarte, now in his fourth full season as crew chief for Earnhardt and his No. 88 Hendrick Motorsports team, announced Thursday he would joint NBC Sports' NASCAR programs starting next year.

"I'm excited for [Letarte] because I know he's really looking forward" to the broadcasting job, Earnhardt said, according to a NASCAR transcript of the news conference. In the meantime, "I'm not worried about this season and how focused we may be," Earnhardt said.

Although Earnhardt has had only one win with Letarte, in 2012, Earnhardt qualified for NASCAR's Chase for the Cup title playoff all three years with Letarte guiding the team. Earnhardt finished fifth in the point standings last season.

"I've grown a lot as a driver working with Steve," Earnhardt said. "I feel confident the team is going to be just fine no matter who the crew chief is. I'm not really worried about whether we'll be able to maintain our consistency and keep getting better."

But Earnhardt added: "The one thing that I fear is just trying to get a guy in there that's equally as talented."

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