OXNARD, CALIF. ? In a stunning move the team wouldn’t explain, the Dallas Cowboys cut Quincy Carter on Wednesday and handed the starting quarterback’s job to 40-year-old Vinny Testaverde.

Just four days after he started camp as the No. 1 quarterback, Carter suddenly was gone from a team he led to 10 wins and back to the playoffs in Bill Parcells’ first season.

Owner Jerry Jones and Parcells were vague about why they released Carter, who started every game in 2003 and was the opening-game starter each of his three years.

“We’ve made a decision to move in a different direction,” Jones said. “We’re not going to get in a lot of detail on the process.”

Jones wouldn’t specifically answer questions about reports that Carter failed a drug test or say if the move was based on nonfootball issues.

“I think that we should leave it at it just was not a difficult decision, and not get into a definition of what it was about,” Jones said.

ESPN.com, FoxSports.com and CBSSportsLine.com, all citing unidentified NFL sources, reported that Carter had failed a drug test. The NFL had no comment.

Carter’s agent, Eugene Parker, did not return calls seeking comment. The quarterback left camp wearing a hooded Cowboys sweatshirt soon after being informed of the decision by Parcells and Jones, and wasn’t available.

Parcells said just this week that Carter had “a leg up” at quarterback. After the first camp workout Saturday, Carter said he was confident of remaining the starter and didn’t consider himself in an open competition for the job.

The coach wouldn’t say why there was such a drastic change in direction.

“I just couldn’t keep him in the plans,” Parcells said. “I’m saddened by this because I’ve got 18 months invested in it … two offseason programs and a regular season and a playoff game.”

Asked why the decision wasn’t made earlier, Parcells said, “We only make decisions based on the information we have.”