Bliss replaces Burton

Burton, 43, joined Haas this year after ten years with Bill Davis, but has expressed doubts about his future with the team during the summer and even questioned his motivation to continue in the Nextel Cup. Burton has recorded just three top 10 finished this season.

Bliss, who drives for Joe Gibbs Racing in the Busch Series, also faces questions about his future with that team. Bliss has had a fairly good season, winning at Charlotte last month. He has made two Cup starts this year and 33 in total, driving most of the 2000 season for the short-lived Jack Birmingham team.

"We've made a lot of changes at Haas CNC Racing this season, and our performance still isn't where we think it should be," said Haas general manager Joe Custer. "We feel like we are capable of a lot more, and putting Mike in the car will give us an opportunity to assess another aspect of the team."

Burton's plans are not clear, although there is speculation that sponsor NetZero may follow him to another team and there are rumours that Burton could join forces with car owner Jim Smith for the final two races, and perhaps beyond.

Burton was asked last week whether he might consider stepping out of full-time racing. He stays busy with his efforts in wildlife conservation and other charities.

"I will say the older you get, the little bit less tolerant you are for it," Burton said. "Being in the middle of this sport, there are a lot of great things about it. [But] there are some things that play on you."