OXNARD, Calif. - Quincy Carter became the Cowboys' starting quarterback three years ago after veteran Tony Banks was unexpectedly cut during training camp. His time in Dallas stunningly ended in a similar way.

In a nearly unexplained move Wednesday, Dallas cut the player who began camp just four days earlier as the No. 1 quarterback. Carter started every game last season, when the Cowboys won 10 games and made the playoffs in coach Bill Parcells' first year.

"Sometimes things happen and you have to alter what you're going to do," Parcells said. "We've put our bets down and the wheel's spinning, so we're not looking back."

Carter was a rookie in 2001 when he became Troy Aikman's successor after Banks was cut. This time, 40-year-old Vinny Testaverde takes over as the starter.

Parcells and owner Jerry Jones were vague about why they released Carter, the team's opening-game starter each of his three seasons and the player Parcells said this week had "a leg up" in the quarterback competition.

Jones wouldn't specifically answer questions about reports Carter failed a drug test or say if the move was based on non-football issues.

"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.

"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."

The NFL had no comment.

ESPN.com, FoxSports.com and CBSSportsLine.com, all citing unidentified league sources, reported Carter failed a drug test. FoxSports.com identified the drug as cocaine.

"I'm shocked. I'm at a loss for words," Carter told The Dallas Morning News. "The one thing I know and the people who have been around me all my life know is that cocaine has never been an issue for me. It never will be. And it's disturbing that a rumor like that would come out. ... That cocaine rumor is ridiculous."

Carter's agent, Eugene Parker, did not return phone messages.

Soon after being informed of the decision by Parcells and Jones early Wednesday morning, Carter left camp wearing a gray hooded Cowboys sweatshirt.

Testaverde reunited with Parcells this summer in hopes of being a starter again. It looks like he will be when the Cowboys open the season Sept. 12 at Minnesota.

"Yes, I believe he'll be the starter," Parcells said. "We're going to have to alter some things in terms of strategy and tailor some things that are more suited for a classic dropback. I am confident in the player, our team will be confident in the player and we will just go forward."

Parcells said that having Testaverde available was "irrelevant" in the sudden decision to cut Carter and that he was "saddened" by the situation.

"I just couldn't keep him in the plans," Parcells said. "We only make decisions based on the information we have."

Carter threw for 3,302 yards and 17 touchdowns in his only full season as the starter, but his 21 interceptions were among the most in the league. He was 16-15 as a starter.

Parcells doesn't plan to bring any more quarterbacks to camp. He will get Testaverde ready to start and give unproven quarterbacks Drew Henson and Tony Romo as many snaps as possible.

Testaverde was a Pro Bowl selection in 1998, when he led the New York Jets to the AFC title game under Parcells, but tore his Achilles' tendon in the 1999 season opener. He lost his starting job to Chad Pennington two seasons ago.

While starting the first seven games last season when Pennington was injured, Testaverde completed 123 of 198 passes for 1,385 yards, with seven touchdowns and two interceptions.

Testaverde, one of just nine players with more than 40,000 career yards passing, said he doesn't have to change his demeanor.

"For the most part, I approach it the same way," he said. "I came here to prepare myself as a starting quarterback. I was competing as if I was going to get the starting job."

The Cowboys traded for Henson, a top prospect out of Michigan who spent the past three years playing baseball in the New York Yankees' minor league system. Romo didn't play during his rookie season.

"Nothing's changed on my part," Henson said. "I'm trying to learn as fast as I can, I'm not trying to accelerate anything. I'm working as quickly and as hard as I can."