Column: USC is 2-0 and untested outside the Sun Belt

Everyone knew it would be a beating.

It was Idaho, for potato’s sake. It was a team that had won three games in the previous three seasons combined. It was a coach with a career record of 2-22.

Everyone knew that Saturday’s game in stifling late-afternoon heat would be a bruising of Coliseum-sized proportions.

But, strangely, in the end, it seems the team most hurt here was USC.

The Trojans 59-9 victory may have looked good on their scoreboard, but did little to liven up their resume, and nothing to strengthen their resolve, which has yet to be tested in two scrimmages this season against the Vandals and Arkansas State.

It gets real, real quick, with Stanford coming to town next week and a visit to Arizona State in two weeks, and are the Trojans ready for that? How can they possibly know whether they’re ready for that?

“All in all, a great win,” said Coach Steve Sarkisian. “We also understand what lies ahead.”

The official price paid to Idaho for their visit was $1.1 million. The real price paid by a team doing virtual calisthenics while the rest of college football’s elite were banging heads could be much higher.

By the time the fourth quarter began, with the Trojans holding a 43-point lead against Paul Petrino’s Vandals and the subs playing, the most excitement among the sparsely populated Coliseum crowd occurred when USC kids began shooting T-shirts into the crowd. Just like that, a vaunted Trojans football game had become a February Wednesday night between the Clippers and Timberwolves.

In the final minutes, the Trojans running backs could be seen dancing in their seats on the bench, and who can blame them? The game was frolicking good fun. Every eligible player played. But here’s guessing fourth quarters in upcoming Pac-12 games will be a little more serious.

“Energy, effort and enthusiasm!” ordered a shouting Sarkisian to his team early Saturday afternoon during a pregame midfield speech.

The Trojans answered with all three. But how much did they need against a team that was vandalized — sorry — in its opener against Ohio (not State) and hasn’t won a game in nearly 11 months?

Cody Kessler followed an unsettled opener by throwing his first beautiful deep balls of the season, touchdown lofts of 50 and 41 yards to JuJu Smith-Schuster and a gorgeous 28-yard touchdown spiral to Isaac Whitney. He wound up throwing for 410 yards and three touchdowns without a pick, which should certainly pump up his slow-starting Heisman campaign.

But how can anyone, including Kessler, trust that he’s growing into a championship-type quarterback by judging him against an undersized defense that last season allowed less than 35 points just once?

The freshman Ronald Jones II looked like the running back version of UCLA’s Josh Rosen with 83 yards in just eight carries with one touchdown and one long run called back for holding. Then there was Adoree’ Jackson, who had one of his usual breathtaking runs after a catch, right side of the field to the left side, up the middle, around and around and finally stopping 30 yards away with everyone just staring at him in awe.

But how can anybody gauge anything against a program that two seasons ago allowed 80 points to Florida State?

It will soon be the middle of September, and we still have no idea whether the eighth-ranked Trojans are really that good, and here’s guessing the Trojans don’t know either, and that can’t do much for their ability to prepare.

Despite blowouts of Arkansas State and Idaho by a combined score of 114-15 — they really buckled that Sun Belt Conference — the Trojans have been blown out by the rigor of the schedules of other top teams who are being built in a far sturdier fashion to handle the potholes ahead.

At the end of Saturday, USC was one of only two top-10 teams that has not played a school from a Power Five Conference. Ohio State played Virginia Tech. Alabama played Wisconsin. And of course, at the same time USC was playing shirts and skins on Saturday, Oregon was growing tougher even in a losing battle at Michigan State.

The Trojans may be 2-0, but it is a soft 2-0 with a hard road ahead.

“I don’t anticipate every game being this way, obviously,” said Sarkisian. “We’re going to be in a lot tighter games than tonight.”

First, Stanford, which, despite its opening loss to Northwestern, still plays the Trojans tough, losing consecutive field-goal games to USC in the last two seasons. Next up, at Arizona State, which beat the Trojans here last year on a Hail Mary pass, and beat them so badly in Phoenix two seasons ago, Lane Kiffin was fired the minute the team plane landed back in Los Angeles.

Later in the season, games at Notre Dame and Oregon complemented by home games against Utah and UCLA fill out a schedule that could end up being one of the nation’s hardest. It’s just too bad the Trojans couldn’t have done more to get ready for it.

It’s not that USC ducks opponents. It is one of only three FBS schools that has never played a team from the small FCS division. It will open next season against Alabama in a national showdown at the Jerry Dome in Arlington, Texas. This year’s schedule was part fluke, part fear, with the Trojans scheduling Idaho two summers ago partially out of concern over how the team would look after enduring four years of probation.

None of this can be completely blamed on the Trojans athletic administration. But all of it now rests on the shoulders of a USC team whose season essentially begins next Saturday.

Undefeated, but untested, uncertain, and three weeks late.

bill.plaschke@latimes.com

Twitter: @billplaschke