Along with dropping their third game in a row, the Dallas Cowboys on Sunday lost quarterback Dak Prescott, who injured his right hamstring in a 27-21 road defeat to the Atlanta Falcons.Replays showed Prescott also nursing a swollen right throwing hand, but there was no immediate word from the Cowboys on the severity.With Dallas (3-5) down 27-13 near the end of the third quarter, Prescott appeared to grimace after a 10-yard pass to Jalen Brooks. He stayed in the game but was ruled out with 11:08 left in the fourth quarter.Making his 36th straight start, Prescott was 18-of-24 passing for 133 yards and a touchdown, along with a season-high 30 rushing yards. The 31-year-old entered the day with 24 rushing yards this season.With Prescott out, Cooper Rush stepped and led Dallas’ comeback bid, tossing for 115 yards and a touchdown. Rush has played sparingly of late behind Prescott, but after the longtime starting QB broke his right thumb in the 2022 season opener, Rush went 4-1 as the starter.