Cowboys coach Jason Garrett hopes that the player will return to training as normal come Thursday, but the incident does suggest that the he has yet to fully overcome a problem that has troubled him in recent years.
"It's gonna pop up," said Romo, according to ESPN. "I'm sure it'll happen throughout the rest of the season. You'll see a day here or there.
"It's the same as the arm. Sometimes your arm gets [tired]. It's just obviously more talked about because of having surgery on the back.
"You play this game. It's a very violent, physical game, and you throw the ball a lot and you do all these things. Sometimes it's just that tightness stuff comes up."
The Cowboys are back in NFL action when they travel to face the St Louis Rams on Sunday.