The Dallas Cowboys are expected to be without star quarterback Dak Prescott for several weeks after he suffered a hamstring injury in the Week 9 loss to the Atlanta Falcons.

According to Jane Slater of the NFL Network, Prescott was initially diagnosed with a partial avulsion of his hamstring tendon. That’s an injury that takes more than four weeks to heal. Slater notes that the 31-year-old is seeking a second opinion on the injury to better determine the best course of action.

Until Prescott gets more opinions on the injury, the Cowboys will hold off on placing him on injured reserve, although it’s certainly possible that Prescott could end up being placed on IR.

With Prescott sidelined, Cooper Rush is expected to serve as the starting quarterback for Dallas, while Trey Lance could serve as his backup. Rush saw action Sunday in relief of Prescott, completing 13 of 25 pass attempts for 115 yards and a touchdown.

Prescott has struggled this season, throwing 11 touchdowns and eight interceptions in his first eight games. He is just one pick shy of his season marks from last season, when he threw nine interceptions in 17 games.

The Cowboys are 3-5 on the year and are looking to avoid a further drop in the standings for the foreseeable future without the three-time Pro Bowl quarterback.