PHILADELPHIA — Carson Wentz has a back injury. The severity is still not known.

Two people familiar with the Philadelphia Eagles quarterback's injury confirmed reports that Wentz has a fractured vertebra, but no definitive determination has been made regarding his status, pending further evaluation.

Both people spoke to The Associated Press on Thursday on condition of anonymity because they weren't authorized to discuss Wentz's injury.

Wentz sat out practice for the second straight day, increasing the possibility Super Bowl MVP Nick Foles will play at the Los Angeles Rams on Sunday night. Wentz wore a red jersey and watched the open portion of practice.

He's seeking more medical opinions before deciding a course of action.

Dr. Andrew Sama, a spine surgeon at the Hospital for Special Surgery in New York, said breaks in the spine can be considered stable or unstable.

"If considered unstable, these breaks usually require surgery to stabilize the spine to allow healing. Stable breaks are usually treated with rest and sometimes bracing," Sama told The AP in an email.

Sama isn't treating Wentz so he doesn't know if he could continue to play through the injury.

"It's hard to say without knowing which vertebra is involved and what kind of break it is," Sama said.

Sama said stable fractures are treated through rest, physical therapy, and sometimes bracing.

"Breaks can sometimes take 6-12 weeks to heal," he added.

Foles hasn't taken a snap in a game since Week 2. He took over in Week 14 last season after Wentz tore two ligaments in his left knee. Foles led Philadelphia to its first NFL title since 1960 and started the first two games this season, going 1-1.

Wentz has 3,074 yards passing, 21 touchdowns and seven interceptions in 11 games this season after finishing third in the NFL MVP voting last year. He has career highs in passer rating (102.2) and completion rate (69.6 per cent).

Foles is 21-12 as a starter, including playoffs, in two stints with Philadelphia.

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