The flight home was interminable. He needed help from the plane to his car just hours after a fourth-down pass to DeMarco Murray with 1:08 to play gave the Cowboys a 24-23 win against the Washington Redskins to keep their playoff hopes alive.
Romo would never get the chance to lead the Cowboys to the playoffs with a victory in the season finale against the Philadelphia Eagles. By the following Friday, he was undergoing a surgery to repair a ruptured disk in his back that would limit him in the offseason and through training camp.
There will be no limitations Sunday when he sees the San Francisco 49ers at AT&T Stadium to start the 2014 season.
Yet San Francisco offers a reminder that Romo's toughness has been on display more than just in that Redskins' game. On Sept. 18, 2011 at Candlestick Park, Romo played most of the game with a broken rib -- and later learned he had a punctured lung -- in leading the Cowboys to a 27-24 overtime win against the Niners.
"Washington was probably the most difficult one to continually play through, but, boy, San Francisco wasn't comfortable," Romo said. "I don't want to minimize that. But when you're playing, you're playing. It's football and you push through everything and you go. Anyone who has ever played understands. You compete. You lay it all on the line, and then you figure out what's wrong with you after."
When Witten left the locker room after halftime, he thought Romo was done for the day. So did coach Jason Garrett. Anthony Spencer didn't know what exactly was wrong with Romo but when he learned his teammate punctured a lung he was amazed.
"You see movies and people getting a punctured lung, spitting up blood or they need to put a hole in their throat to get the pressure off them," Spencer said. "I don't know how he did it."
Romo's parents were in the stands that day. When their son was not on the field for the start of the second half, they made their way down to the field to see if they could find out what was wrong.
By the time they got to the field, Romo was back in the game.
"Once again, when you're sitting at 0-1 where we were at the time, it was one of those games starting off 0-2 makes it very difficult to come out of that hole," Romo said. "You can do it, but it's very difficult. That third quarter, actually watching the game on TV, our season I felt it was coming down to that last quarter and a half or whatever, so I kind of hid from the doctor for a second and then ran out on the field."
The Cowboys trailed 21-14 when Romo returned. With 11 minutes to play, they were down 10 points.
In the fourth quarter, Romo completed 11 of 14 passes for 124 yards and a touchdown pass. He directed the tying drive that ended with Dan Bailey's 48-yard field goal on the final play of regulation. In overtime, he and Jesse Holley connected on a 77-yard pass to set up Bailey's winning kick.
"He comes off the field and his mom wants to hug him," Romo's father, Ramiro, said. "He says to his mom, 'Don't hug me, mom. Don't hug me. I can barely breathe right now.' "
Witten called the experience, "surreal." Murray, a rookie at the time, said it was "unbelievable."
The adrenaline from an overtime win masked some of the pain, but Romo had difficulty buttoning his dress shirt and carrying his bag to the bus after the game. His parents made a trip to Napa for a wine vacation when they got a call the next day that their son had a punctured lung in addition to the broken rib.
He played the next week and did not miss a start, needing a pain-killing injection and titanium-plated protective vest for most of the next two months.
"Nothing surprises me anymore, but anytime it's your son or your daughter or whoever, you can't help but be a parent and want nothing but safety for your son or daughter, you know what I mean?" Ramiro said. "You don't want anything happening to them and most assuredly you don't want him to get any more injured more than they are already."
Romo's parents will be inside AT&T Stadium on Sunday. Ramiro said he and his wife, Joan, will always cringe when they see their son get hit. They will say multiple prayers that their son -- and every player on the field -- will not get hurt.
"This is a violent game," Ramiro said.
That's the backdrop as Romo begins his eighth full season coming off his second back surgery in less than a year. He has played through injury before, including the last meeting against San Francisco, and he will have to do it again.
He turned 34 in April and there are questions as to whether he can withstand not only a full season but whether he can improvise the way he has in the past. Romo doesn't mind the skepticism about whether he can do it, but he is not skeptical.
"I think I'll be better," Romo said.
He said he won't think about the back and ways to protect himself. He said he won't change the way he plays.
"When you play," Romo said, "you've just got to go play."
Just as he did three seasons ago against San Francisco with a broken rib and punctured lung.