The Dallas Cowboys’ training camp was overshadowed by the spectacle of Terrell Owens, the high-profile wide receiver who skipped practices with a hamstring injury and attracted attention to himself while riding a stationary bike on the sidelines. Owens was a distraction until Sunday’s opener, when he showed that the quality of his play can eclipse his misbehavior. But the sub-par play of Cowboys quarterback Drew Bledsoe means a new controversy could be brewing in Dallas.

Bledsoe completed only 16 of 33 passes and threw three interceptions in a 24–17 loss to the Jacksonville Jaguars. For Bledsoe, it was an old story: At times he showed the talent that has made him a four-time Pro Bowler. He completed five of his first six passes for 85 yards as the Cowboys jumped out to a 10–0 lead. But as the game wore on, he showed why two teams — the New England Patriots and Buffalo Bills — gave up on him. The Jaguars’ pass rush started getting to him, he began to look rattled, he threw one interception to set up a game-tying Jacksonville touchdown at the end of the first half, and two more interceptions in the fourth quarter as the Cowboys’ 10–0 lead turned into a 24–10 deficit. Even Bledsoe’s one touchdown, a 21-yard pass to Owens late in the fourth quarter, was an ugly throw that Owens turned into a score by adjusting his route with the ball in the air and snatching it away from two Jacksonville defenders in the end zone.

Cowboys coach Bill Parcells has had four NFL head coaching jobs (with the Giants, Jets, and Patriots before going to Dallas), and in all of them he has stressed the importance of avoiding turnovers. He won’t tolerate a quarterback who throws three interceptions in a game. If Bledsoe continues to play as he did Sunday, he won’t continue to play for Parcells. But Parcells also shows loyalty to veteran players who have played well for him in the past, and Bledsoe led the 1996 Patriots to the Super Bowl with Parcells as his coach.That’s why Parcells has insisted — at least publicly — that he’s behind Bledsoe. “Don’t make anything out of this, because Bledsoe is starting next Sunday,” Parcells said at his Monday press conference.

But if Bledsoe throws three more interceptions in Sunday’s game against the Washington Redskins and the Cowboys fall to 0–2, the pressure will start to mount on Parcells to give backup Tony Romo, who has never thrown a pass in a regular-season NFL game, the opportunity to show what he can do. Parcells has done all he can to prepare Romo to play, taking the unusual step last month of having Romo play every snap of an exhibition game (he was the first NFL quarterback to do that since the otherwise-forgotten Cary Conklin did it for the Redskins in 1992) so that Romo could get as much experience as the preseason allows.

In four preseason games, Romo completed 64 of 92 passes for 833 yards and looked as though he understands how to run the Cowboys’ offense, which he has studied as the team’s backup quarterback for the last three years. Romo played well enough in this year’s preseason that Dallas released Drew Henson, the former Yankees minor league prospect and a pet project of Cowboys’ owner Jerry Jones, and made Romo the team’s only backup quarterback. The Cowboys already had Romo under contract for a league-minimum salary, but they showed their commitment to him by giving him a two-year, $3.9 million contract extension during training camp.

Parcells has made no secret that he wants to see what the 26-year-old Romo can do. He isn’t a great runner, but he’s more mobile than the lead-footed Bledsoe, which could make him a better fit for a Cowboys team that has a shaky offensive line. As a senior at Eastern Illinois in 2002, Romo won the Walter Payton Award, an honor that goes to the best Division I-AA football player in the country. Several winners of that award, including Philadelphia Eagles running back Brian Westbrook, Baltimore Ravens quarterback Steve McNair, and former Giants, Patriots, and Jets running back (and Parcells favorite) Dave Meggett have gone on to have productive NFL careers. Immediately after saying Monday that Bledsoe would start, Parcells added, “But we’ll see what goes on this week. I told you I was getting Romo ready to play. And at some point in time, I’m hopeful I will be able to play him this year.”

Bledsoe has faced a similar situation once before. In 2001 with the Patriots, Bledsoe started the first two games of the season but got hurt in the second after being leveled by Jets’ Mo Lewis. Backup Tom Brady played well enough in his place that coach Bill Belichick kept Bledsoe on the sidelines after he recovered, the Patriots won the Super Bowl, and Bledsoe lost his job for good. Romo hasn’t done anything on an NFL field yet to indicate that he has the ability to become another Tom Brady, but to start in Dallas Romo doesn’t have to be better than Brady — he just has to be better than Bledsoe.

If Parcells benches Bledsoe, he needs to be sure that he’s making the right decision because Bledsoe likely won’t take it well. When Bledsoe left the Buffalo Bills in 2004, he chose the Cowboys in large part because of his pre-existing relationship with Parcells. Bledsoe is durable (his last serious injury was the one five years ago that paved the way for Brady’s arrival), but at 34 he has to think he has limited time left in the league. He doesn’t want to spend any of that time standing on the sidelines.

But Parcells, who is expected to retire at the end of the season, has even less time left than Bledsoe, and he badly wants to win a third Super Bowl ring this season. Winning a championship with an unproven quarterback like Romo seems unlikely, but winning one with a quarterback who plays the way Bledsoe did in the opener would be impossible.

Mr. Smith is a writer for FootballOutsiders.com.