DIXFIELD — A word of warning to Oak Hill or any other opponent trying to trick the Dirigo secondary.

They may be junior-dominated, but the Cougars’ defensive backs are fully grown men when it comes to keeping trade secrets.

“We’ve got a lot of experience in our secondary with me, Mike (Casey) and Gavin (Arsenault),” Riley Robinson said. “We all played secondary last year, so we’ve got a year of experience under our belt. Coach (Jim) Hersom really stresses that … you know … I can’t really tell you. He stresses what our roles are, and we go over it a lot.”

If the other teams in Class D West are seeing Dirigo’s tendencies on film, or hearing about it through the grapevine, it isn’t helping much.

The ability of Arsenault and Robinson to intercept and knock down passes has been the defensive highlight this season for No. 2 Dirigo (7-1), which hosts No. 3 Oak Hill (8-1) at 7 p.m. Friday in a regional semifinal.

Arsenault had a fumble recovery and an interception to highlight four forced turnovers in a 14-6 win at Oak Hill on Sept. 13. It avenged a loss to the Raiders in the 2013 regional championship.

“It’s been a fun season,” Arsenault said.

And as is often the case in two-way, Class D football, when Dirigo has the ball, quarterback Robinson and wide receiver Arsenault spend their time making other secondaries look a step slow.

Arsenault caught two long touchdown passes in the first five minutes of an early-season victory over Winthrop. He and Robinson have struck in other games, as well, often after the defense has run itself ragged trying to tackle 235-pound fullback Tyler Frost.

“They’ve got to put at least nine people in the box to stop Tyler,” Robinson said. “That opens up our pass game.”

The emergence of halfbacks Joe and Mike Casey has balanced Dirigo’s offense, as well.

“When you have fast halfbacks like Joe Casey, and they’re keying on Tyler, it just opens up the air,” Arsenault said.

None of those skill players would have achieved as much, however, without the rebuilding of an offensive line that was gutted by graduation.

“It’s gotten better,” Arsenault said. “We’ve had linemen who were playing running back last year, and they’ve gotten into the line.”

“Our offensive line does a great job,” Robinson added. “I’ve had a great time this year. Our wide receivers like Gavin are running great routes and making plays for me. A lot of times they’re making unbelievable catches, which make me look good.”

Frost is the centerpiece of the defense, also, persuading other teams to run wide and try to work the flats.

Many have found that to be a game-changing mistake.

“When you’ve got great middle linebackers like Joe Casey and Tyler Frost, they’ve got to throw the ball,” Robinson said. “We can’t do anything without that. They stop the run, and we’ve got a great defensive line with Matt Irish, Bryce Whittemore, Bennett Dorion, Vincent Hebert. They get in there, they cause pressure, and it can lead to easy picks for us.”

Dirigo jumped out to a lead on Joe Casey’s return of the opening kickoff for a touchdown in the first meeting with Oak Hill.

Whether it’s a product of defense, special teams or offense, Robinson hopes the Cougars follow that blueprint on Friday.

“It was great having Joe Casey take that one to the house. It was the perfect start for us and the worst thing they could imagine,” he said. “It’s always great to get the first score, because you’re feeling confident going on defense. You have all the momentum.”

Dirigo and Oak Hill are meeting for the seventh time since 2011, and the fifth in Robinson’s career.

The quarterback says back-to-back losses to Winslow and Oak Hill in the regional final would be enough to fuel his fire, regardless of the rivalry.

“We’ve seen a lot of their games. They’ve seen a lot of our games,” Robinson said. “It’s just going to come down to who is better (Friday) night.”

No secrets? Sure.

koakes@sunjournal.com