Will Boise State enter the College Football Playoff race in 2015?

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Boise State's first season under coach Bryan Harsin was a success. The Broncos won 12 games, including a 38-30 victory over Arizona in the Fiesta Bowl.

Boise State is back among the nation's top 25 teams in 2015 with 17 returning starters. Replacements must be found for quarterback Grant Hedrick and running back Jay Ajayi, but the Broncos are loaded for another run at a double-digit win season.

An offensive overhaul

The Broncos return nine offensive starters but still will look dramatically different this year. The two lost starters -- quarterback Grant Hedrick and tailback Jay Ajayi -- accounted for 89.1 percent of the team's yards and 92.4 percent of the offensive touchdowns. The program also changed offensive coordinators again. Tight ends coach Eliah Drinkwitz was promoted to become the fifth man in six years to orchestrate the Broncos' offense. He replaces Mike Sanford, who left after one successful season at his alma mater to become the coordinator at Notre Dame. Drinkwitz previously called plays for coach Bryan Harsin in 2013 at Arkansas State.

The quarterback and tailback holes won't be filled until August. Sophomore Ryan Finley, the backup last year, is the favorite to replace Hedrick. He tossed two touchdown passes in relief last year against Air Force. Sophomore Jeremy McNichols, who played a receiver/tailback combo role as a true freshman, is the front-runner for Ajayi's job, but coaches expect to utilize a committee this season rather than the one-back approach of 2014.

The two new starters will be surrounded by talent, including standout offensive linemen Marcus Henry (center) and Rees Odhiambo (left tackle); emerging pass catchers Thomas Sperbeck, Chaz Anderson and Jake Roh (tight end); and veteran receiver Shane Williams-Rhodes.

The defense looks stacked

The Broncos return all but one defensive lineman, two outstanding linebackers and two all-conference defensive backs from a defense that lacked consistency but showed flashes of dominance last season.

The goal is to regain the conference's top spot in defense, a perch the Broncos have occupied frequently during their run of 10 top-25 seasons in 13 years. They turned stingy for a four-and-a-half-game stretch from halftime of the San Diego State game to the end of the season. The biggest flaw last year was giving up the big play, an area that should improve with this group's experience and the return of the nickel back. The Broncos were forced by injuries to move linebacker Tanner Vallejo to nickel, which limited their coverage options. Vallejo, who was the Defensive MVP of the Mountain West Championship Game and Fiesta Bowl, returns to middle linebacker after recording 16.5 tackles for a loss.

Other defensive standouts include Mountain West sack leader Kamalei Correa (12.0), MWC interception leader Darian Thompson (seven, with one TD) and cornerback Donte Deayon (six interceptions, two TDs).

Experience among the specialists

Junior Tyler Rausa replaces solid kicker Dan Goodale, while Sean Wale returns as the punter, coming off a career-best performance in the Fiesta Bowl. Long snapper Kevin Keane and holder Wale return, too. Williams-Rhodes and Deayon provide dynamic options as kick returners, though the Broncos did rank last in the league in kickoff returns in 2014 (18.8-yard average).

Boise State's 2015 outlook

The Broncos' 12-2 record and Fiesta Bowl victory were a surprise in 2014. This team is much better equipped for that type of season with its experience, depth and stable coaching staff. The Broncos might be unanimous favorites in the Mountain West and should start in the top 25. The key will be a loaded September schedule: The opener is against Washington and former coach Chris Petersen in Boise, and trips to BYU and Virginia follow. A 4-0 September would rekindle the buzz that surrounded the program's Kellen Moore era as an outsider trying to crash the national championship party. But even with a difficult start, the schedule strength will allow the Broncos to contend for another New Year's Six berth.