Ertz won the job for a second straight year. He suffered a season-ending knee injury last year on the first play from scrimmage against South Dakota and has yet to throw a collegiate pass.
"He's in all reality just been more consistent than the other two," Snyder said. "That's extremely important to us."
Senior Joe Hubener, who started 11 games last year, and redshirt freshman Alex Delton will serve as the backups to Ertz. He was voted a captain by his teammates and was considered the favorite at the start of camp to earn the starting position.
"Jesse pulled himself away," Snyder said of the quarterback competition. "I would say, in the last four days, being able to have a greater consistency on the practice field."
Hubener threw for 1,837 yards, rushed for 613 yards and accounted for 22 touchdowns last season as K-State finished 6-7.
"Jesse has a huge upside because of his speed, his accuracy throwing. He obviously knows the offense extremely well at this time," Kansas State offensive coordinator Dana Dimel said. "As you remember the first game last year he was a starter, so you have a returning starter as far as knowledge goes, but you don't have a returning starter as far as experience goes. His biggest attributes are his knowledge of the offense and his overall speed as a runner."
The Associated Press contributed to this report.