AJ Allmendinger will drive the No. 51 Phoenix Racing Sprint Cup car Sunday at Martinsville Speedway.
Allmendinger, who was suspended earlier this season for violating NASCAR's substance abuse policy, has driven the past two races at Charlotte and Kansas, where he finished 24th and 35th, respectively.
Phoenix Racing general manager Steve Barkdoll said the decision to go with Allmendinger was based on how he has performed over the past two weeks.
Allmendinger finished second at Martinsville in April while driving for Penske Racing. He has four consecutive top-15 finishes at the 0.526-mile track.
Allmendinger was suspended by NASCAR in July for failing a random drug test, and fired by Penske shortly after. He was reinstated in September after completing NASCAR's recovery program.
Barkdoll said it remains a race-by-race decision. He said Regan Smith would have been in the car for the rest of the year had he not been called on to replace Dale Earnhardt Jr. in the No. 88 the past two weeks.
Barkdoll did not rule out the possibility that Smith could be in the car in two weeks at Texas.
Smith told ESPN.com he doesn't have a ride for Martinsville, but he is hopeful he'll get an opportunity at Phoenix Racing before the end of the season and into next year.
He understood the decision to stick with Allmendinger this week after Allmendinger basically replaced him when Phoenix Racing gave him permission to replace Earnhardt Jr. for two races while Earnhardt recovered from a concussion.
"It's a situation where they had to get ready for Martinsville,'' Smith said. "They've got to build racecars and get cars ready to roll. I don't think the door is shut.''
Smith added he remains in talks with JR Motorsports for a fulltime Nationwide Series race in 2013.
"It would be a great opportunity over there if all that works out,'' he said. "It's a championship-caliber race team. That's what drivers want, the opportunity to go win races and championships.''
Information from The Associated Press was used in this report.