LOS ANGELES — With Marcus Mariota and Jameis Winston leading two top-notch offenses into the Rose Bowl on Thursday, almost everybody expects this College Football Playoff semifinal to feature plenty of points.

Oregon’s Don Pellum and Florida State’s Charles Kelly are in charge of preventing that seeming inevitability, but these two rookie defensive coordinators are used to doing difficult work.

“We’re not going to be changing the game plan,” Pellum said. “After 13 games, you’re not going to change it. We just have to execute.”

There’s a certain similarity to the paths followed by Pellum and Kelly to Pasadena.

When the Ducks and Seminoles needed new defensive coordinators early this year after the departures of two high-profile predecessors, both schools shunned mercenary hires and promoted veteran assistant coaches to the most prominent jobs of their careers.

Neither defense had a spectacular season under its new management, struggling with injuries and occasionally producing lamentable defensive results.

Yet both clearly have been good enough to earn a national title shot, and Kelly and Pellum both express pride in their work — albeit tinged with the awareness that their jobs are about to get a whole lot tougher.

“We knew there would be some challenges, but at the same time, I think our guys have stepped up,” Kelly said. “Are we the same team? No. But I’m very proud of what our guys have done and how they have hung in there together and fought through.”

Kelly had moved from Georgia Tech to Florida State just one year before his promotion, taking over when Jeremy Pruitt left the Seminoles for Georgia after only one season in Tallahassee — and just eight days after Florida State beat Auburn in Pasadena for the national title.

Kelly is Jimbo Fisher’s third defensive coordinator in three years, starting with Mark Stoops’ departure for Kentucky.