Dr. Saturday will unveil its preseason Top 25 team-by-team during the next 25 days. This list is based on returning starters, schedule and prospects. However, we all know that once the games begin, things can change very quickly. Still, we thought we’d give our best guess heading into the 2015 season.

No. 24 Boise State

2014 record: 12-2, 7-1 Mountain West

Returning starters: 9 Offense; 8 Defense

2015 Outlook: Coach Bryan Harsin’s first season could not have gone any better. The Broncos blazed through most of their schedule (sans a surprising loss to Air Force), won the Mountain West Mountain Division, won the conference title game, became the highest-ranked Group of Five team in the country and went on to defeat Arizona in the Fiesta Bowl.

But this year, there will be a few challenges.

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Quarterback Grant Hedrick and running back Jay Ajayi, who accounted for 89.1 percent of Boise State’s yards and 92.4 percent of the offensive touchdowns, are gone, leaving the Broncos to plug those holes. However, there are nine starters returning to an offense that ranked 14th in the country in total offense (494.3 yards per game) and ninth nationally in scoring offense (39.7 points per game).

Defensively, Boise State should be stout even if the numbers might not reflect that. The Broncos got into some track meets last year while allowing 26.8 points per game. Even though this defense should be better, the Mountain West is a high-scoring conference and the inflated numbers shouldn’t change much. Still, the Broncos best and most experienced playmakers are probably on the defensive side of the ball.

As shocking as it sounds, Boise State can be better than a year ago and an undefeated season is a strong possibility. It opens the year against Washington and former coach Chris Petersen, which is a winnable statement game at home. Outside of BYU the following weekend, there are few challenges on what appears to be a pretty favorable schedule. Look for the Broncos to once against represent the Group of Five in a New Year’s Eve bowl.

Player to watch: Tanner Vallejo, LB

Vallejo had a historic season last year. He had 100 tackles and 16.5 tackles for loss, which was a Boise State FBS record. He was named the MVP of the Mountain West Championship game and the Fiesta Bowl. And he did all of this while playing outside his natural position.

Vallejo spent the bulk of last season at nickel (strongside linebacker) because iof injuries to other players, but this year he moves back to middle linebacker, his favored spot. That puts him closer to the football and poised for an even bigger season.

Vallejo is one of 10 returning starters on a defense that is loaded with talent. If there was one problem with Vallejo playing out of position, it was the propensity to give up the big play. But he should have more help on the outside this season with players returning from injury.

Breakout player: Ryan Finley, QB

Finley, a redshirt sophomore, is the only quarterback on the Boise State roster with experience and while he hasn’t officially been named the starter, he’s the favorite to win the job. He had limited experience in five games last year, mostly in a loss against Air Force after Hedrick was pulled following four picks in the first half. For the season, Finley completed 12 of 27 passes for 161 yards with two touchdowns and one interception.

Don’t expect the Boise State offense to change too much with Finely under center. It was pretty balanced a year ago and, with Jeremy McNichols likely filling the running back role, should be again. Eliah Drinkwitz is the program's fifth offensive coordinator in six years, but he did lead Harsin's Arkansas State offense in 2013.

The biggest obstacle for Finley this fall camp is gaining the trust of his teammates and staying on the good side of his coaches. Finley was arrested in April on misdemeanor charges of a minor consumption or in possession of an alcoholic beverage and resisting or obstructing police officers. He’s due in court in late September, but Harsin said during Mountain West media days that Finley has done everything he needed to get back into the good graces of the coaching staff and won’t face a suspension.

Miss one of our Top 25? No. 25 Wisconsin.

For more Boise State news, visit Blue-Turf.com.

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Graham Watson is the editor of Dr. Saturday on Yahoo Sports. Have a tip? Email her at dr.saturday@ymail.com or follow her on Twitter! Follow @YahooDrSaturday

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