It's still early and other teams like Fresno State and Utah State will likely factor into the title race. Still, it isn't implausible to assume that the Broncos and the Aztecs could end up facing one another twice this season.
Boise State (3-1, 1-0 MW) opened conference play by dominating Wyoming 34-14, bouncing back from a loss to Oklahoma State a week earlier. San Diego State (3-1, 0-0) has run off three straight wins since falling to Stanford in the season opener. The biggest highlight in that stretch came in the form of a 28-21 victory over then-No. 23 Arizona State.
The Broncos lead the all-time series 3-2. The Aztecs haven't beaten Boise State since snagging back-to-back wins in 2012 and '13.
San Diego State at Boise State
Kickoff: Saturday, Oct. 6 at 3:30 p.m. ET
Spread: Boise State -14
Three Things to Watch
1. Defense vs. defense
If you're looking for a high-octane score fest, you might leave feeling disappointed. Boise State and San Diego State enter the game as two of the top defensive teams in the Mountain West.
The Broncos rank second in the league in total defense (322.3 yards per game) and scoring defense (21.3 points per game). Twice this season, Boise State has held opponents under 300 total yards. The Broncos allowed Wyoming to gain 295 yards and limited Connecticut to 193 yards.
San Diego ranks third in both categories, behind the Broncos, allowing 337 yards and 21.5 points per contest. The Aztecs boast an elite rush defense that keeps opposing offenses from getting on track. San Diego State has defended 122 rushing plays this season and has not allowed a run longer than 16 yards. They rank second nationally in allowing 64.5 yards per game on the ground and 2.1 yards per carry.
2. How will injuries impact San Diego State's offense?
The injury bug bit San Diego State hard in September. Several key players on offense have been sidelined by injuries suffered in recent games. Christian Chapman has been out since suffering an MCL sprain against Sacramento State. Zachary Thomas tore an ACL a week later against Arizona State. Juwan Washington broke a collarbone against Eastern Michigan.
Weathering these injuries will hinge on well their replacements can keep the offense moving. Chase Jasmin will earn the start in the backfield on Saturday in place of Washington. Jasmin has run for 233 yards in four games and is averaging 5.4 yards per carry. Ryan Agnew has already been filling in for Chapman at quarterback with favorable results. In two starts, Agnew has thrown for 305 yards, three touchdowns, and one interception while completing 52.2 percent of his passes.
Their ability to get it done on offense will go a long way to determining if San Diego State can win for the 15th time in the team's last 18 road games.
3. Terrific trio pacing Boise State
Boise State can point to depth at receiver as a big factor for strong play on offense through four games. The Broncos are one of only five schools – along with Hawaii, Texas Tech, Washington State, and West Virginia – to have three different receivers rank among the top 100 FBS players in receiving yardage per game.
Sean Modster is leading the way with 96.3 yards per game, good for 19th nationally. A.J. Richardson ranks 54th with 78.3 yards per contest. John Hightower checks in at 97th in the FBS with 64.3 yards per game. The trio have combined for 955 receiving yards and eight touchdowns over Boise State's first four games.
It has helped Brett Rypien get off to a strong start during his senior season. Rypien has thrown for 1,389 yards and 12 touchdowns while completing 70.1 percent of his passes so far. He ranks second in the Mountain West in completion percentage and third in total passing yards.
Once again, Boise State looks like the team to beat in the MWC's Mountain Division, with only Utah State posing a serious threat to the Broncos. San Diego State has a good enough defense to make life hard for the Broncos' offense. Injuries have taken their toll on the Aztecs' offense though and it may be tough for them to do enough to keep up with Boise State for four quarters.
Prediction: Boise State 31, San Diego State 20
— Written by John Coon, who is part of the Athlon Contributor Network. Coon has more than a decade of experience covering sports for different publications and outlets, including The Associated Press, Salt Lake Tribune, ESPN, Deseret News, MaxPreps, Yahoo! Sports and many others. Follow him on Twitter @johncoonsports.