FRISCO, Texas — Dallas Cowboys quarterback Dak Prescott is dealing with a partial avulsion of his right hamstring, which means part of the tendon has pulled away from the bone, a source confirmed Wednesday.

Prescott has not yet been put on injured reserve. If he is put on IR, he would sit out a minimum of four games, which would keep him out until at least Dec. 9 against the visiting Cincinnati Bengals should such a move be made this week. But two sources said Prescott probably would need a longer recovery period than four weeks.

NFL Network first reported the nature of Prescott’s injury.

Prescott was hurt after a 5-yard scramble late in the third quarter of Sunday’s loss at the Atlanta Falcons. On the next play, cameras caught him grimacing as he threw a wobbling 10-yard pass to Jalen Brooks. After the game, he said he had not had that feeling before.

“I felt it when I was getting up from the run. I can’t even say that I felt it running,” Prescott said. “The tackle, maybe something on the tackle. Yeah, I don’t know. But when I was standing up, I felt something, actually. Didn’t think it was much. You get tired. It’s a physical game. A lot of times you feel different things and they kind of go away.”

Prescott had an MRI on Monday, and a source told ESPN’s Adam Schefter then that the quarterback would be out several weeks.

In 2022, Cowboys left tackle Tyron Smith sustained a full avulsion of his hamstring in a training camp practice that required surgery. He sat out the first 13 games of that season.

The Cowboys will start Cooper Rush at quarterback in Prescott’s absence. Rush is 5-1 as Prescott’s replacement, including a 4-1 stint in 2022 after Prescott sustained a broken right thumb in the season opener. Rush has nine touchdown tosses, six interceptions and 1,786 passing yards in 30 appearances.

Trey Lance will serve as the backup.

“Cooper’s been great in getting Dak ready to play, and now Dak, they’ll be some role reversal there,” Dallas coach Mike McCarthy said. “[Rush’s] temperament is excellent. I would say he’s as even-keeled as an individual, especially a quarterback, that I’ve had the opportunity to work with. Cerebral. Smart. He gives you the flexibility to continue to play. I think that’s what you want in all your quarterbacks. You don’t want to get to a spot where you have to change a bunch of things offensively because who’s behind center.”