Patrick Carpentier was released from Gillett Evernham Motorsports on Tuesday.
Carpentier, a Sprint Cup rookie and former open-wheel racer in Champ Car and the IndyCar Series, was the driver of the No. 10 Dodge for GEM. He could not be reached for comment.
On his Web site, patcarpentier.ca, Carpentier wrote he got into an argument and skirmish Saturday with team director Mike Shiplett, who blamed him for failing to qualifying at Talladega.
"I think it's a complete lack of respect," Carpentier wrote. "I never was shy to take the blame when I thought it was my fault, but here, everybody knows that it's like driving in a straight line. The driver just has to keep the steering wheel straight. He should have taken a time out and calmed down before he spoke."
Carpentier was one of two drivers who failed to make the field for the Amp Energy 500, but his qualifying lap was faster than both of his teammates, Kasey Kahne and Elliott Sadler, who had guaranteed spots and weren't in qualifying setups.
"I know [Shiplett's] criticism didn't make any sense," Carpentier wrote. "What is worst is that he seems to have forgotten pretty quickly races like Dover or in Atlanta where I've qualified a car that he himself didn't think was fast enough to earn a place on the starting grid. I realize now that some people have a really short memory span in NASCAR."
Dominic Fugere, motorsports writer for Le Journal de Montreal, reported Shiplett later apologized to Carpentier after the argument at Talladega.
Carpentier already was a lame duck at GEM, which announced earlier that Reed Sorenson would drive for the team in 2009.
Mark McArdle, the team's vice president and managing director of competition, said Wallace brings a wealth of experience to the No. 10 team.
"We appreciate Mike stepping in and helping us out. A.J. had a commitment and Mike was gracious enough to give us a hand. He's a good driver and we expect that will show this weekend."
Allmendinger, 26, is committed to driving the No. 00 this weekend at Charlotte.
"We certainly appreciate all the effort that Patrick Carpentier made for us this year. But, our job is to put ourselves in a position to win races plus we're striving to get the No. 10 into the top 35 in points. We feel A.J. gives us the best chance to do both," said McArdle.
Terry Blount covers motorsports for ESPN.com. He can be reached at firstname.lastname@example.org.