DOVER, Del. — Kyle Busch couldn't resist taking a poke at the driver who replaced him at Hendrick Motorsports.

Busch's career has skyrocketed since signing with Joe Gibbs Racing, while Dale Earnhardt Jr.'s sagging career has hit an all-time low. On Wednesday night, team owner Rick Hendrick had had enough, firing Earnhardt's long-time crew chief Tony Eury Jr. in a move to try to salvage the season.

"It's never Junior. It's always the crew chief," said Busch, who wonders when fans might finally blame NASCAR's most popular driver for his slumping start.

NASCAR's most popular driver, Earnhardt is 19th in points and coming off a season-worst 40th-place finish at Lowe's Motor Speedway.

"Eventually, I'm going to be the one that has to answer about how much I lived up to my father's name," Earnhardt said Friday at Dover International Speedway.

And he's ready to take the heat from anyone who wants to take shots — even Busch.

"He's always had a chip on his shoulder for me," Earnhardt said. "I expect any opportunity to throw a jab at me, he'll do it. That's just his personality."

Earnhardt understands that without Eury Jr. around to deflect criticism, it's up to him to find the spark that will jolt the No. 88 into contention for the Chase for the championship.

Earnhardt couldn't say why the pairing with his cousin flopped, but he pointed the finger for the back-of-the-pack finishes at himself.

"I take full responsibility for making some mistakes along the way, especially this year," he said. "I would say I haven't been on my game. I shoulder any amount of responsibility that's necessary and everybody feels is fair."

Team manager Brian Whitesell will call the shots this weekend at Dover. Next week, Lance McGrew, who has previous crew chief experience in the Cup series with former Hendrick driver Brian Vickers, will take over on an interim basis at Pocono Raceway. McGrew, who's working with Brad Keselowski this weekend, said making the Chase for the championship is still the goal for this season.

Earnhardt finished last in the 12-driver Chase field in 2008. This season, Earnhardt is a whopping 203 points out of the 12th place cutoff for the Chase. He's had three top-10 finishes and six finishes of 27th or worse.

Hendrick driver Jimmie Johnson said Eury will work with his team next week on road course testing because crew chief Chad Knaus will be unavailable.

Earnhardt and Eury spent Tuesday and Wednesday testing on the road course at Virginia International Raceway. Hendrick told them he was splitting them up when they returned Wednesday evening.

Busch said the Eury-Earnhardt combination hasn't been clicking since last summer.

"You've got to make the most popular driver in the sport competitive, so you got to do what you got to do," Busch said. "He's the one who brought that crew chief on. He's the one who pulled so hard to bring Eury in."

Busch has 10 Cup wins for JGR since the start of the 2008 season. Eury Jr. and Earnhardt left Dale Earnhardt Inc. last season to drive for Hendrick Motorsports. Despite driving for NASCAR's top team, they had just one win in 48 races with Hendrick.

Earnhardt is well behind well teammates Jeff Gordon (first), Johnson (fourth) and Mark Martin (12th) in the points standings.

"There's no substantial differences in how the No. 88 is being run versus the other teams," Whitesell said. "I do feel the personalities and the fact of them being family may have been a factor."

Whitesell and Earnhardt will get their first crack at working together on the No. 88 during qualifying later Friday.

"As far as him getting better, I feel his talent is exactly where he needs to be," Whitesell said.