Romo's return to health after missing 12 games last year with a fractured clavicle was the foundation of hope for a bounce-back season and playoff run following last year's 4-12 campaign.
Now Romo is out again because of a fractured bone in his back.
But the Cowboys are not moping around licking their wounds. They are focused on winning games during his absence behind rookie quarterback sensation Dak Prescott, who will start against the New York Giants in the Sept. 11 season opener and newly signed veteran Mark Sanchez will be the backup.
Vice president Stephen Jones still has a good feeling about Dallas after training camp and the preseason.
"I really like our football team," Jones said. "Obviously, no one is naive when you lose your starting quarterback for some time, which it's obviously going to be some time. That certainly wasn't in our plans; you certainly hope something like that doesn't happen.
"Obviously, Dak's emergence makes you feel better about having that happen to you because there is a lot of optimism with Dak. Other than that, our team has exceeded our expectations in training camp and guys have performed well and done a really nice job for us. We really feel good about our team."
And there is Sanchez, listed behind Prescott.
"Mark is very excited to join one of the flagship organizations in the NFL," said Andrew Kessler, Sanchez's agent. "He had numerous opportunities once the Broncos parted ways with him and he felt the Cowboys were the best fit for a variety of reasons."
Sanchez has started 72 games in a six-year career, going 37-35 in those games.
Sanchez has thrown for 15,126 yards in his career with 86 touchdowns and 84 interceptions. He has a career passer rating of 74.3.
The Cowboys are also able to look forward with optimism because of what they have seen from Prescott in the preseason. They know the regular season will be different, but Prescott gives them something to feel good about.
It's not the same uncertainty without Romo as it was a year ago.
"Teams like to game-plan and they scheme against you, so he's going to see some looks he hasn't seen before," cornerback Brandon Carr said of Prescott. "At the same time, a lot of veteran guys ... will get him well prepared. He's going to see it all. That's part of growing up in this game."
The Cowboys believe they can succeed with Prescott because of the team they have around him -- the same Romo-friendly set-up that was there to take pressure off of the injured 13-year veteran is there for the rookie.
The biggest questions remain on defense, where the Cowboys don't have any pass rushers of note because of the suspensions of defensive ends Randy Gregory and DeMarcus Lawrence.
Gregory is out four games and possibly more for violating the NFL's substance abuse program. Lawrence will also be sidelined the first four games.
The Cowboys are hopeful they have some players to hold the fort in the interim.
"I will say this -- we've seen some things in camp that we like from our defensive linemen," Jones said. "I think we're athletic and I think they're going to play hard and (defensive coordinator) Rod Marinelli has coached them up and I think we'll do some good things."
--The Cowboys are carrying two fullbacks in Rod Smith and Keith Smith and Jameill Showers has initially stuck as the fourth quarterback behind Romo, Prescott and Sanchez.
The team did cut three former draft picks -- wide receiver Devin Street (5th rounder in 2014), defensive end Ryan Russell (5th rounder in 2015) and tight end Rico Gathers (6th rounder in 2016).
Running back Darren McFadden was placed on the non-football injury list, meaning he won't be eligible to play in the first six games. Defensive end DeMarcus Lawrence was placed on the reserve/ suspended list. He will miss the first four games for violating the league's substance-abuse policy.