Broncos right guard Ron Leary left in the third quarter with a concussion.
Connor McGovern replaced Leary. McGovern, a fifth-round pick in 2016, had never played a down in the NFL before Monday night.
Leary left the Cowboys as a free agent to sign a four-year, $35 million contract with the Broncos, including $20 million guaranteed. He started 47 games at left guard in four seasons in Dallas.
In 2015, Leary lost his starting job to La'el Collins but got it back in 2016 when Collins was injured in Week 3. Leary’s play drove up his price in free agency, making him too expensive for the Cowboys to keep and a key addition to the Broncos’ revamped offensive line.