Romo, who missed last Sunday's 28-17 loss to the Arizona Cardinals with his third back injury in the last 18 months, made the trip to England but stayed at the hotel while the rest of his teammates practiced at Allianz Park.
"It's just based on the feedback, and what he's told us how he feels," Cowboys coach Jason Garrett said. "Is it more worthwhile to stay there and get treatment, or come over here and watch practice and stand up for a couple of hours? It makes sense to stay there and get some treatment."
The Cowboys (6-3) face the Jacksonville Jaguars (1-8) on Sunday at Wembley Stadium, the last of three regular-season NFL games in London this year.
Instead of Romo, backup Brandon Weeden took the snaps during practice on Wednesday. Weeden, who was dumped by Cleveland two seasons after getting drafted in the first round in 2012, threw two interceptions against Arizona and couldn't get the Dallas offence into the end zone until the game was out of reach. He now has 25 touchdowns and 27 interceptions in his career.
Garrett, however, remained optimistic that Romo would be ready for Sunday.
"Obviously, all these things are medical decisions. Really important for our medical team to weigh in on what our players have," Garrett said. "Getting feedback from the player, as to how they feel, how they handle the workload, is really, really important. And then you come up with what you need to do during the week to get them prepared to play their best on Sunday."
Romo has fractures in two small bones in his back. The injury is unrelated to a herniated disk sustained last year and to off-season surgery to remove a cyst earlier in 2013.
Despite the focus on Romo and how he's feeling, Garrett said the attention was a not a distraction for Weeden, who was 18 of 33 for 183 yards with one touchdown as the Cowboys dropped their second straight game last weekend following a six-game winning streak.
"There's a lot of media attention on the NFL, on the Cowboys, and certainly if you're the quarterback of the Cowboys, there's a lot of media attention that comes with that," Garrett said. "If you're that guy, or someone around that guy, it's just part of the deal. It comes with the dinner, as they say, and you get yourself ready to go."
Even if Romo says he is ready to go and given clearance by the medical team, Garrett and his assistants will make the ultimate decision based on his performances in practice.
"We as coaches, the football people, we're most interested in function, how is the player functioning," Garrett said. "He might say 'this,' the doctor may say 'this,' but what we see is 'this.'
"We have to make the best decision during the week to get him ready to play on Sunday."
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