Dak Prescott’s hamstring injury could potentially keep him on the shelf for longer than initially hoped.

Prescott’s initial diagnosis is that his hamstring tendon partially tore off the bone, which is known as a partial avulsion, NFL Network’s Jane Slater reported on Wednesday.

The recovery timeline for such an injury generally is more than four weeks, per Slater. Prescott currently is seeking additional opinions on his injury, Slater added.

Cowboys owner Jerry Jones said Tuesday that Prescott was likely headed to injured reserve, which would sideline him a minimum of four weeks.

Cooper Rush is set to start for Dallas on Sunday against the Philadelphia Eagles, but if Prescott misses more than a month, it will be worth monitoring to see if Trey Lance, No. 3 on the depth chart, gets some run.

Prescott, who agreed to a four-year, $240 million extension this season, has completed 64.7% of his passes for 11 touchdowns and eight interceptions this season.

Dallas (3-5) hosts Philadelphia (6-2) at 4:25 p.m. ET on Sunday.