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SAN DIEGO -- No. 19-ranked San Diego State has not played Mountain West Conference counterpart Boise State since 2014, a byproduct of the league's divisional split. However, Aztecs running back Rashaad Penny spoke of facing the Broncos on Saturday as if he was preparing for Rivalry Week.

"We're taking this game like it's a championship game," Penny said. "It's a big week. Emotions are pumped up. … I feel the energy already, and it's only Monday."

Excitement should indeed reach a crescendo once kickoff arrives Saturday night at SDCCU Stadium, although "rivalry" might oversell the significance. The 2014 game was just the programs' fourth meeting ever.

But when they last met, comments San Diego State head coach Rocky Long made -- that Boise State's famed blue turf carried no "mystique" -- were met with retort when Boise State head coach Bryan Harsin declared his Broncos "do the talking on the field" following a 38-29 win.

San Diego State (6-0, 2-0 Mountain West) is one of just 13 squads in the Football Bowl Subdivision still undefeated. The Aztecs have a Heisman Trophy contender in Penny, who leads the nation in all-purpose yards, and they are two-time defending Mountain West champions.

Even so, Penny said San Diego State is an "underdog" when paired with Boise State (3-2, 1-0), a sentiment attributable to the Broncos' national prominence.

Boise State is the Mountain West's "market name," according to Long.

"From the Rocky Mountains east, nobody watches. But they did watch them in the Fiesta Bowl beat Oklahoma (in January 2007)," Long said. "They did watch them beat Arizona in the Fiesta Bowl (in December 2014). So, if you go past the Rocky Mountains, they know who Boise (State) is, and they don't know who the rest of us (in the Mountain West) are.

"Doesn't make them any better than Colorado State," Long added. "Doesn't make them any better than us."

Penny was a freshman for the 2014 meeting, when he rushed one time for 1 yard.

That's a world away from Penny's 2017 production of 993 yards on 143 carries. His 170 yards at UNLV last Saturday night marked Penny's sixth game reaching triple digits on the season.

"He's got more rushing yards than 82 Division I teams, so that's pretty impressive," Harsin said in his weekly press conference. "He runs physical, he runs hard, and he's really consistent."

Quarterback Christian Chapman has effectively balanced the run-heavy San Diego State offense with explosive passing plays. He made frequent use of receiver Mikah Holder at UNLV, finding Holder nine times for 144 yards. The emergence of a steady possession target, and the big-play ability of tight end David Wells, who has touchdowns on two of his six receptions, add a dangerous element to the Aztecs' attack.

The Boise State defense has not allowed a 100-yard rusher through five games. The closest was Virginia's Jordan Ellis, who averaged only 3.9 yards per carry on his way to 93 yards.

The Broncos are coming off a dominant performance against Brigham Young, winning 24-7. BYU was the third opponent Boise State held to 14 points or fewer.

However, Long points to a game in which the Broncos allowed 47 points as an example of Boise State's potential.

"It was 31-17 at the start of the fourth quarter," Long said of Boise State's 47-44, triple-overtime loss at No. 8 Washington State on Sept. 9. "They should have beat Washington State, and Washington State's in the Top 10.

"They had a bad break at Washington State. (Otherwise) they'd be ranked ahead of us."

The "bad break" was the absence of quarterback Brett Rypien, who sustained a head injury in the early going. Rypien made his return Sept. 22 against Virginia, but really found his stride last week against BYU.

Rypien threw his first touchdown of the season and completed 63.2 percent of his attempts, providing a complement to the ground game. Running back Alexander Mattison obliged with his first 100-yard rushing game of the season, totaling 118 and two touchdowns.

"If we play like we did in this last game, we put ourselves in position to play our best game," Harsin said. "Which we need to."

Saturday's matchup is important to both programs, to be sure. But even if emotions are heightened, as Penny suggested, the two head coaches share common ground on one point: It takes on no greater importance than any other matchup before or after.

"Arizona State was the most important game," Long said. "We beat Arizona State, Stanford's the most important game of the year. We beat them and now -- now -- we're at the seventh game of the year, and this is the most important game. What happened to all those other important games? What happens to all the other important games after this?"