Sometime after the Cowboys returned to Dallas following their victory at Washington on Sunday, quarterback Tony Romo received an epidural injection to relieve pain and reduce inflammation related to the herniated disk in his lower back, according to sources.

It is typically two or three days before doctors can determine whether the injection has succeeded. This is the normal conservative treatment protocol for such a back injury, and the Cowboys hope that it enables Romo to recover in time to play in Sunday night's winner-take-all matchup with the Philadelphia Eagles.

But sources close to the quarterback consider that a long shot and remain skeptical he can safely play and function as an NFL quarterback, especially in such a short time.

"I would be very, very surprised if he got back on the field," one source said.

At this time, Romo has been advised that he likely will need surgery eventually, but sources say that no such procedure has been scheduled.

Doctors often treat patients with epidurals to block pain and promote healing. Often, multiple injections are required over time before the patient's symptoms dramatically improve. It is also possible the damage is such that the injections will not provide relief.

If Romo does not play Sunday, Kyle Orton will get the start. The team also agreed to a deal with 41-year-old Jon Kitna, pending a physical, the Cowboys confirmed on their website Tuesday night.

Information from ESPNDallas.com's Todd Archer was used in this report.