It is a wild arm, a wondrous arm, a winning arm.

But is it powerful enough to restore a reputation?

It is a stalwart presence, a swaggering presence, a saving presence.

But is it powerful enough to rescue a coach?

Jayden Maiava brought quarterback chills back to the Coliseum on Saturday afternoon in leading USC to a 28-20 victory over underwhelming Nebraska.

But can he take the heat off Lincoln Riley?

Maiava is good. He’s three touchdown passes good. He’s one rushing touchdown good. He’s lead-the-team-on-a-fourth-quarter-clinching-drive good.

But is he good enough to settle the ground under Riley’s uncertain footsteps?

That was the larger question looming over the Trojans as they pulled off a bowl-saving victory on a sunny afternoon when a new quarterback and new resilience showed up for the same old coach.

Is it too little, too late?

The 5-5 Trojans need to beat either UCLA or Notre Dame to qualify for a bowl and some semblance of stability as they finish Riley’s third season.

No, Riley is not getting fired, not even after going 7-10 in his last 17 games and failing for the third time in three years to qualify for the College Football Playoff.

At this moment, it costs too much to can him, as much as $60 million by one estimate. But a third consecutive poor finish combined with the arrival of a new university president could mean that if the Trojans don’t make substantial improvements next season, removing him becomes priceless.

That means one more bad season would be his last season, which means he would become a lame duck.

And the Trojans do not need the most celebrated football coaching hire in their history to become a lame duck.

Transfers don’t flock to lame ducks. Donors don’t pony up for lame ducks. Fans turn their backs on lame ducks.

Even though he’s not getting fired, Riley needs to coach these last two regular-season games and possibly a bowl game like he’s coaching for his USC life.

And so, 11 days ago, he shed Miller Moss and buckled into a personal flotation device named Jayden Maiava.

USC quarterback Jayden Maiava runs with the ball during the second half Saturday against Nebraska at the Coliseum.

(Gina Ferazzi / Los Angeles Times)

Riley knows what he is doing. All of USC knows what he is doing. Riley needs this to work. The entire Trojans family needs this to work.

The atmosphere at the Coliseum on Saturday was lukewarm at best, a hollow homecoming, loads of great Nebraska fans often making more noise than their Trojans seatmates.

For a pleasant afternoon game in the heart of November, this was not a Pete Carroll crowd, it was a Clay Helton crowd, and that just won’t do.

It feels like some in the Trojans family already have given up on Riley, and those who are undecided are waiting to see how this season ends.

Yeah, it’s pretty apparent, Riley’s future is now inexorably tied to Maiava.

And, wouldn’t you know it, less than six minutes into the game, the kid threw a pick-six, former Trojan Ceyair Wright taking a wild throw 45 yards in the other direction and knocking the Trojans flat.

“Sometimes deals like that, especially at home, can take the air out of your sails a little bit,” Riley said.

But no, not on this day, not with this quarterback.

“The team didn’t even flinch,” Riley said, and neither did Maiava, who followed his slow start with a stretch of nine consecutive completions for 100 yards and two touchdowns en route to a 25-for-35 afternoon for 259 yards and lots of gasps.

The kid takes chances. He throws up what looks like a jump ball until you realize the pass actually is directed to a leaping receiver. One such no-no-yes pass was a 28-yard hurl to Duce Robinson to set up the Trojans’ first touchdown.

Said Maiava: “I saw Duce when I got flushed out the pocket. I tried to give him a ball that was his ball or nobody’s ball.”

Said Robinson: “I’ve said it before, and I’ll say it again — he’s a playmaker. When you have an arm like that, of course you’re gonna have confidence in it.”

Maiava throws over trouble, around trouble, and sometimes directly through trouble. Two of his biggest completions — a 12-yard touchdown pass to Kyron Hudson and a nine-yard pass to Makai Lemon on their clinching drive — were balls that bounced off Nebraska helmets.

And Maiava just kept flinging.

USC quarterback Jayden Maiava passes in front of Nebraska linebacker John Bullock during the second half of the Trojans’ 28-20 win Saturday at the Coliseum.

(Gina Ferazzi / Los Angeles Times)

“That’s just who he is,” linebacker Easton Mascarenas-Arnold said. “He’s going to take risks. Some go his way, some don’t. That’s just kind of why I think he’s a great player. He’s willing to take those risks over and over again, regardless of the play before.”

Maiava certainly has that aura. He strode into the postgame press conference room with an easy smile while offering the sort of what’s-up greeting that one doesn’t normally get from nervous young quarterbacks.

“I’ve got a great team, a great coaching staff, there’s nothing for me to worry about, but just to go out there and play ball with them,” he said.

He not only passes with abandon, he runs the same way. His rambling style caused an unforced lost fumble that led to a Nebraska field goal, but he also deftly handled a fourth-down pitch to Woody Marks that went for 34 yards and led to Maiava’s two-yard, clinching touchdown run.

“Coach Riley was in his bag,” Maiava said. “Regardless, I think we were gonna get the first.”

Riley indeed called a great play there, and Trojans fans hope his sideline work will be just as inspired now that he has a new leader.

“He did a good job staying in the moment,” Riley said of Maiava. “He gave guys opportunities to make plays … It showed some poise … I thought he handled it well.”

Riley seems well aware of the importance of these final games. He surely knows much of his program’s future will be determined right now.

“We talked to them a lot about this three-game stretch here at the end and what an opportunity it is for us,” he said. “And we got it started off on the right foot today.”

Back in August, this space presented the query that was foremost in the mind of the increasingly uneasy Trojans family.

“Can Lincoln Riley coach?” I wrote. “That is the question that will hover over the program from the Sept. 1 Louisiana State opener through the completion of USC’s first Big Ten season.”

For some, the question has been answered, and it is a resounding no.

But for others, the question is still there, still hovering, endlessly, ominously, perhaps reliant on these last two or three games.

So, Jayden Maiava, welcome to Lincoln Riley’s brave new USC football world.

Now save it.