"It's never Junior; it's always the crew chief," said Busch, who fired the opening shots when asked about team owner Rick Hendrick's dismissal of Tony Eury Jr. as Earnhardt's crew chief a day earlier.
Busch's salvo was not taken lightly by Earnhardt.
"He's always had a chip on his shoulder for me," Earnhardt said of Busch, "so I expect any time he gets an opportunity to throw a jab in there he's going to do it. That's just his personality."
Earnhardt replaced Busch at Hendrick Motorsports last year, but since then Busch, driving for Joe Gibbs Racing, has won 11 Sprint Cup races to Earnhardt's one.
Asked about Eury's replacement, Lance McGrew, with whom Busch worked in the Nationwide Series at Hendrick in 2004, Busch expressed sympathy for McGrew.
"He's got his hands full, I guess, having to deal with what's going on," Busch said. "And if Junior doesn't run well, then he [McGrew] is going to be the 'problem' again."
Said Earnhardt: "That doesn't really surprise me. We're working toward how we can make our deal work, and that has nothing to do with Kyle."
Busch said he understood the move to bolster a driver with Earnhardt's star power but weak performance of late.
"You've got to make the most popular driver in the sport competitive, so you gotta do what you gotta do, I guess," Busch said.
Busch added, "He's the one who brought that crew chief on; he's the one who pulled so hard to bring Eury Jr. in [along with Earnhardt in his move from Dale Earnhardt Inc.].
"It looked like it was working there in the beginning," Busch continued, "and it just hasn't worked since the summer of last year, really. So, whatever makes them better, I guess."
Busch, since being squeezed out in favor of Earnhardt and over salary differences with Hendrick, has vastly out-performed Earnhardt since the beginning of 2008. And Busch has made no secret of his pride in that.
Not only has Busch won 11 races to Earnhardt's one, he is currently sixth in points, well within Chase criteria, while Earnhardt is 19th after 12 races. No driver has ever come from 19th at this point of the season to make the Chase. Greg Biffle made the biggest leap, from 19th to 14th, in 2007.
Veteran Jeff Burton expressed more sympathy for Eury -- who has been under intense fire for months from Earnhardt's fans -- than for anyone else in the shakeup.
"I have a lot of respect for Tony Eury Jr.," Burton said. "I've seen him be part of making an awful lot of race cars go fast, including the cars that Junior was driving.
"If you go back just two years ago [when Earnhardt and Eury were together at DEI], there were an awful lot of races that Junior had chances to win, and compete at a very high level, and had problems," Burton said.
"I think the fans have been excessively hard on Eury Jr.," Burton continued. "I feel bad for him about that. At the same time, Junior can get it done, too.
"For whatever reason, it wasn't working, and sometimes you just have to make a change."
Hendrick promised Thursday that "everyone in our company" will be involved in the effort to bolster Earnhardt, including "all of our drivers."
Said Jimmie Johnson: "As a teammate, I need to do everything that I can to explain my car and answer any questions that Junior may have, and in our debrief sessions, explain as much as I can. The same for Jeff [Gordon] and Mark [Martin]."
Asked whether Earnhardt has been absorbing debrief information, or whether he needs to absorb more, Johnson said, "I've been impressed by both [Earnhardt and Eury in the debriefs].
"Dale Jr. is on time to those meetings, and that's a pretty big statement, on a funny note," Johnson said, referring to Earnhardt's career-long reputation for not being an early riser or particularly punctual. "One time we came in the truck and he had food and drinks for us set up. So that's all being on the funny side.
"But on a real note, I've seen a great commitment out of both of them. Before they worked at Hendrick, the rumors were around that maybe there isn't the focus or the commitment.
"And all that stuff is BS. Both of those guys are extremely committed and extremely focused on what they're doing. And that's what makes this so tough," Johnson continued. "When the results aren't there and the effort is there, it's a hard world to live in."
The shift of Hendrick personnel and resources to focus on Earnhardt's effort "is not that unusual," said HMS senior driver Jeff Gordon. "It is unusual in that it's Junior and it's a very high-profile driver. You know there's going to be a lot of media attention, and that's the biggest challenge.
"Within the organization we've had similar situations before," Gordon continued. "I've been there 17 years, so we've seen a lot of changes.
"My role is not going to be really any different from what it has been. That's just to give my opinion, my thoughts on what I see and what I hear in our debriefs."
Ryan Newman of the Hendrick satellite Stewart-Haas team pointed out that beyond engineering, "It's a people business and you have to work together as a group. You have to have that chemistry that creates that gel that keeps everybody together.
"Performance is a part of that, attitude is a part of that, ego is a part of it -- your mannerisms can be a part of that," Newman said. "It's just part of sports in general. Every team goes through that, whether they're a team within an organization or a basketball team out there fighting against another team.
"It's about the people, and sometimes you have to make those changes -- that's the bottom line."
"With the crew chief changes that I've had, there's really not a set thing you have to learn about somebody -- it either works or it doesn't," Edwards said. "You either run better or you don't, and there's no way to really tell how that's going to happen."
Ed Hinton covers NASCAR for ESPN.com.