Michael Gehlken of the Dallas Morning News noted they were unable to reach a contract agreement before the 4 p.m. ET deadline.
Negotiations between Prescott and the Cowboys have been a significant topic throughout the offseason. The two-time Pro Bowler is already under contract for 2020 after signing his one-year franchise tender worth $31.4 million on June 22.
Per Sports Illustrated's Mike Fisher, one key difference for Prescott and the Cowboys when they were talking about an extension was how many years it would be.
Fisher noted the Cowboys were offering a five-year deal worth $35 million per season with "virtual guarantees of in excess of $106 million," but Prescott preferred a four-year contract that gave him the ability to test the market after his age-30 season.
As things stand now, Prescott could become a 27-year-old free agent if the Cowboys don't re-sign him or use the franchise tag on him after next season.
Dallas is in a difficult position since a second consecutive franchise tender for Prescott would cost it $37.7 million, per CBS Sports' John Breech.
The Cowboys currently project to have $36.1 million in cap space for 2021, per Over the Cap.
While that will be a concern for Jerry Jones and his front office to worry about in the future, the Cowboys have secured short-term security since Prescott has already signed his franchise tender and doesn't appear inclined to holdout.