LOS ANGELES – On the day before Clay Helton tabbed Max Browne as USC’s starting quarterback in August, he expressed the desire that his decision would last for at least several games.

“Hopefully, it’s seasons to be honest,” he added.

That plan began. Browne started USC’s first three games.

But the Trojans saw their worst start since 2001 charecterized by struggles on offense. In high-profile games against Alabama and Stanford, they mustered one touchdown and scored a combined 16 points.

The leash became short.

On Monday, Helton announced that San Clemente High graduate Sam Darnold would replace Browne as USC’s starting quarterback, beginning on Friday at Utah.

“I wanted to see a spark in our offense,” Helton said, “and I think Sam provides that. I’m confident in it.”

Helton, who is in his first full season as the Trojans’ coach, met with Darnold and Browne to inform them of his decision on Sunday night. He told the rest of the team Monday.

“I was stoked about it,” Darnold said. “I was stoked to finally get that opportunity.”

Browne, the former top-ranked high school quarterback from Sammamish, Wash., originally beat our Darnold, a redshirt freshman, in training camp, ending a tight competition that began in spring practice.

Helton said he did not question his decision to name Browne the starter last month.

“I’ll never regret going with that young man to start off,” he said.

In three games, Browne completed 55 of 87 passes for 474 yards, two touchdowns and two interceptions.

“It surprised me for sure,” Browne said. “I’d be lying otherwise.”

Helton thanked Browne for his effort and his professionalism.

“He is not the reason we’re 1-2,” Helton said. “He’s not the scapegoat here.”

Browne, the strong-armed, 6-foot-5 passer, lamented missed opportunities in his recent starts. Several of his deep throws downfield against Stanford were overthrown or the timing with his target was off.

“If you connect on a few of those, it changes kind of the vibe of statistically and the vibe of the offense,” he said. “ So I look back on a few of those routes and you’re kicking yourself a little bit, because that’s kind of what I’ve made my money on out here.”

He did not throw a touchdown or interception against the Cardinal.

“It was not that Max played bad,” Helton said. “You look at the numbers and the efficiency. But the ball wasn’t getting into the end zone.”

Darnold took the majority of the first-team reps in practice on Monday afternoon.

“He has shown he can be an every-down guy,” Helton said. “He’s shown elite arm strength and a uniqueness to run the ball.”

When Browne was the starter, Darnold came in for certain red-zone packages. That will not be replicated. Browne will not rotate in barring injury.

The change at quarterback comes on a week where the Trojans have only six days between Pac-12 games at Stanford and Utah.

That remained of little concern to Darnold. He has played in each of the first three games this season, completing 14 of 22 passes for 136 yards, two touchdowns and one interception in three games. He also rushed for 12 yards.

He pointed to his preparation. He said he emulated Browne, who was the backup for the past three seasons behind Cody Kessler. He always was ready, he said.

“I took that mindset,” Darnold said. “I think on Friday it is going to pay off.”

The last time the Trojans started a freshman by choice was in 2009 when it turned to Matt Barkley, who debuted in the opener against San Jose State.

In 2012, Max Wittek started the final two games for an injured Barkley, a senior at the time.

It is also the first time USC has voluntarily made a midseason quarterback change since 1998, when then-coach Paul Hackett turned to freshman Carson Palmer over Mike Van Raaphorst.

For Browne, he expected this decision to stick. He said he did not anticipate winning the starting job back.

“I know how these things work,” he said. “Usually once the young guy goes, you know how it is. But I’ll be ready. I owe it to my teammates and the guys I’ve been with for four years now. I’ll be ready.”

The fourth-year junior waited behind Kessler three years for the chance. Under NCAA rules, he can transfer to another school without penalty after this season since he has graduated.

He intimated it was an option he would explore.

“You think about all the possibilities at hand, but at the end of the day, it’s only Week 4,” he said. “There’s a lot of ball to play.”

Darnold expressed optimism about a seamless transition between the two signal-callers who developed a close bond over the course of the competition this offseason. At one point, they bought matching red Razor scooters.

“It (stinks), but it’s a business,” he said. “It’s a coach’s decision. It’s nothing between us.”

Contact the writer: jkaufman@scng.com