Romo landed on his shoulder during a strip sack by linebacker Jordan Hicks. The 35-year-old quarterback previously broke his left clavicle in Week 7 of 2010, forcing him to miss the rest of the season.
"I'll be back," Romo told FOX Sports' Erin Andrews after the game. "It's going to take a little bit of time. It's a broken bone. It is what it is."
Since the injury happened a month earlier this time around, the organization is unlikely to make any rash decisions on his status. More tests will be run on Monday.
Offensive coordinator Scott Linehan will have to change gears, as Weeden simply doesn't have the touch or field vision for a ball-control passing attack.
The coaching staff did everything they could to limit Weeden's impact in one spot start last season, only to watch their replacement quarterback fail to complete a single pass to a wide receiver in the first half of a losing effort.