IRVING (AP) — Not even the great optimist Jerry Jones could have expected a start like this.

The Dallas Cowboys are 3-0 and boast the most productive offense in the NFL. They have a budding star in Tony Romo and a defense that’s getting better every week.

And their next two games are against winless teams who’ve just lost their offensive stars.

Is there any doubt they’re going to be 5-0?

Whoa. That’s exactly the kind of over-optimism coach Wade Phillips is worried about following an impressive win over the reigning NFC champions at their place Sunday night. So when he spoke to the team Monday afternoon, he opened with a different kind of math lesson, pointing out that they’ve only played 19 percent of the season, which means there’s 81 percent to go.

“You are not measured on 19 percent,” he told them. “You are measured on the whole season.”

Still, Phillips has to like what he’s seen so far:

Dallas has scored 116 points, the last 34 against a Chicago defense widely considered among the best in the league. The way Romo avoided the rush and kept finding receivers legitimized their success against less-than-stellar units the previous two games. The pass-heavy game plan that included Terrell Owens starting several plays lined up in the backfield also showed the creativity of new offensive coordinator Jason Garrett.

“It’s exciting, against that defense, to do what we did,” Romo said.

The new defensive scheme Phillips is implementing seems to be coming together, too.

There were questions whether his pressure-heavy plan would work with the players he inherited after they allowed 35 points in the opener. Then Dallas gave up 20 points. Now 10. Plus, the Cowboys had their top cornerback, Terence Newman, for the first time in the last game. Coincidence or not, that game also featured the first two sacks of the year for should-be sack leader DeMarcus Ware.

“Everybody is very excited around here,” defensive captain Bradie James said. “The city is buzzing. Our confidence is definitely high. … We’re showing some flashes of what we can be. There’s still some things we have to work on, no doubt. But we know that we’re putting in the work and the foundation is getting set.”

Then there’s the schedule.

St. Louis (0-3) comes to Texas Stadium on Sunday without running back Steven Jackson, followed by Dallas going to Buffalo to play a Bills club that’s 0-3 and might be without quarterback J.P. Losman.

Should the Cowboys win both, as expected, Romo, Terrell Owens and Marion Barber will be able to say they’ve already done something Troy, Michael and Emmitt never did: win their first five games. The Triplets’ best start was 4-0 in 1995, the season of Dallas’ last Super Bowl title. The Cowboys haven’t been 5-0 since 1983.

With such lowly foes coming up, some are already talking up the sixth game, at home against New England. There’s a good chance both teams will be unbeaten for their Oct. 14 matchup.

Beyond that, the Cowboys can look forward to adding Tank Johnson to the defensive line in November. They’re also hoping to have deep threat Terry Glenn back later this season.

“I think this team can be a better football team in five or seven weeks, when we get all the guys healthy and Tank joins the club,” Romo said. “I think it could be a lot of fun.”