It is the third time in Darrell Hazell's three seasons at Purdue that the Boilermakers have changed starting quarterbacks in September or October.
Appleby started the first three games of the season along with the final seven games in 2014. He had an awful performance in Saturdays' 51-24 loss to Virginia Tech, completing only 9 of 28 passes for 110 yards and two interceptions, along with a fumble that was returned for a touchdown. In two losses, Appleby has been intercepted a total of six times.
Blough will be making his first start Saturday when Purdue (1-2) hosts Bowling Green (1-2). Blough completed 3 of 7 passes for 11 yards in the fourth quarter against Virginia Tech and is 3 of 8 for the season.
"You deliberate over it for a couple of days and make sure you think everything through," Hazell said Tuesday. "You don't want to make any quick judgment. Austin's created energy and leadership for us. The one thing that we have stressed -- and will continue to stress -- is the importance of taking care of the football. We need to do better at that position."
Blough challenged Appleby for the starting job throughout spring practice and during training camp in August, but Appleby did not turn the ball over and was thorough directing the offense.
But in the 41-31 season-opening loss at Marshall, he was intercepted four times, two of which were returned for touchdowns. He bounced back to throw four touchdown passes without being intercepted in a 38-14 victory against Indiana State on Sept. 12 but directed only one touchdown drive against the Hokies.
Purdue's two other touchdowns against Virginia Tech were a 90-yard fumble recovery return and a long fourth-quarter touchdown run by freshman Markell Jones when the Boilermakers were trailing 41-17.
"I am not going to say that I was surprised, but it caught me off guard a little bit," Blough said after practice Tuesday. "As you can imagine, I was pretty stoked. Everybody wants to win and get headed in the right direction.
"I am not going to worry about keeping it, because then you press and make mistakes and end up losing. I am going to be myself, relax and have fun. I am going to enjoy playing the game that I love."
Appleby replaced Danny Etling after five games of the 2014 season, and played well in his first start, a victory at Illinois. But Appleby was 0-6 in his final six starts of the 2014 season and now is 2-8 in 10 starts.
Once known as the "Cradle of Quarterbacks," Purdue has struggled at that position during the past six seasons with a different player leading the team in passing each year. Purdue is also just 5-22 in Hazell's first 27 games.
Hazell likes Blough's potential to create positive-yardage plays.
"He keeps the play extended and keeps his eyes down the field," Hazell said of the quarterback from Carrollton, Texas. "He can make the throws that we need him to make. One of the things I said to him was, 'You don't have to play outside yourself, just play within the scheme of the offense and don't feel like you have to be the guy that makes all these different plays.' "
Purdue plays at No. 2 Michigan State on Oct. 4. Hazell said that was not a factor in getting his young quarterback experience now.