Boise State's Bryan Harsin is set to become the next head football coach at Auburn, a source confirmed to ESPN's Adam Rittenberg.

He replaces Gus Malzahn, who was fired earlier this month after eight seasons with the Tigers.

The 44-year-old Harsin is 69-19 with three Mountain West titles in seven seasons at Boise State, his alma mater. Harsin was a top target for Auburn from the start of its coaching search, and more than 20 Power 5 schools have reached out to him over the years, a source told Rittenberg.

Louisiana head coach Billy Napier and Clemson defensive coordinator Brent Venables previously turned down the Auburn job, sources told ESPN's Chris Low.

Malzahn's firing came as somewhat of a surprise after a 6-4 season and cost the school more than $21 million to buy out the former coach's contract.

Auburn has been an up-and-down program, winning the national championship under Gene Chizik before going on a rapid decline.

The Tigers turned to Malzahn, the offensive coordinator for that Cam Newton-led team. Malzahn led Auburn to the SEC championship and into the national championship game in his first season, 2013. But the Tigers have lost at least four games in each of the seven seasons since.

Meanwhile, Auburn's chief rivals have thrived. Alabama has been a perennial contender and Georgia has also emerged as a national power, making it even harder for Auburn to make headway on the field and on the recruiting trail.

The Tigers sought out their next coach from more than 2,100 miles away.

Harsin also replaced Malzahn at Arkansas State in 2013, winning a share of the Sun Belt Conference title in his lone season before returning to his alma mater.

A victory in the 2014 Mountain West Championship game marked Boise State's first outright league title since joining the conference in 2011, and the first overall since 2009. The only alumnus to lead the Broncos as head coach in the history of Boise State, Harsin has won conference championships as a player, assistant coach and head coach.

Boise State won at least 10 games in each of his first six seasons. The Broncos are 5-2 this year after losing to No. 19 San Jose State in the league title game. Boise State opted not to participate in a bowl game.

Auburn is set to play No. 15 Northwestern in the Citrus Bowl on New Year's Day. Defensive coordinator Kevin Steele is serving as the Tigers' interim coach and was initially regarded as a candidate for the permanent job.

Yahoo Sports first reported Auburn was narrowing its search to Harsin, and The Athletic was first to report the agreement.

The Associated Press contributed to this report.