Chelf, who started the final five games last season after starting the year as the third-stringer, and Walsh, who was 2-1 in three starts and was named Big 12 Offensive Freshman of the Year by the league coaches, have been battling for the starting job throughout the fall.
Chelf threw for 1,588 yards and 15 touchdowns with six interceptions a year ago while leading the Cowboys to victories over West Virginia, Texas Tech and Purdue in the Heart of Dallas Bowl.
Walsh passed for 1,564 yards and 13 touchdowns with three interceptions, and compiled a 170.11 quarterback rating last season that was the fourth best ever by a freshman (trailing only Michael Vick of Virginia Tech, Sam Bradford of Oklahoma and Rudy Carpenter of Arizona State).
Gundy following the spring game in April that he would no longer talk about the quarterbacks, and they would be off limits to the media, until after the season opener against Mississippi State.
"I don't like two-quarterback systems if we hae one that's better than the other or one that's more experienced. Each year is different. Now we have two quarterbacks who are right there with the same amount of experience," Gundy said.
"We are obligated to give both of them an opportunity to play. We feel like they can each provide something to the team to give us a chance to be successful this year."