SALT LAKE CITY — Robbie Connolly’s second gig with The Killers put him in front of 100,000 screaming rugby fans.

The occasion: the AFL Grand Final — Australia’s Super Bowl equivalent — hosted in the enormous Melbourne Cricket Ground. (Melbourne’s home team, the Richmond Tigers, pulled off an upset over the Adelaide Crows that day.) During The Killers’ postgame concert, Richmond goal kicker Jack Riewoldt jumped onstage and sang “Mr. Brightside” with the band.

The crowd was, to put it lightly, raucous.

“I think it was definitely baptism by fire,” Connolly said with a laugh during a recent phone interview, when the band had a day off in New Orleans between shows.

The Provo-based musician grew up in Salt Lake City and attended Dilworth Elementary, Clayton Middle School, East High School and the University of Utah. He also plays in the Utah band Fictionist, and has been one of The Killers’ backup musicians since September. He’ll return to Utah when The Killers play at Vivint Arena on Tuesday, Feb. 6. So far, Connolly has played nearly 50 shows with the world-famous band, including gigs at Austin City Limits and London’s O2 Arena. And he’s got a lot more to go: The Killers’ current tour might extend into 2019.

New Killer, new father

Joining The Killers on a worldwide tour is a big undertaking, no matter how you cut it. That the tour started two weeks after Connolly’s wife, painter Caitlin Connolly, gave birth to twin boys, made things a bit more complicated.

“I’d never been a father at all, let alone a father of two babies,” Robbie Connolly said. “And to be going through that at the exact same time that I’m going through planning this big career change, I just had no idea what to expect.”

Those twins were a long time in the making: Robbie and Caitlin Connolly had been married for 10 years when they decided to try in vitro fertilization. That method increases the likelihood of twins, and they got the big news before the gig with The Killers presented itself.

Neon Trees bassist Branden Campbell, a fellow Utah County resident, had grown up performing with Killers drummer Ronnie Vannucci Jr. Campbell told Connolly The Killers were looking for an additional rhythm guitarist to join them on tour, but Connolly said he kept the opportunity at arm’s length initially. Leaving his wife and newborn twins wasn’t exactly ideal.

There were other reasons for his skepticism. Fictionist had signed with Atlantic Records in 2011, but the label shelved the band’s album and dropped Fictionist two years later. He knew brushes with the big time don’t always go smoothly.

Caitlin Connolly, however, told him, “Of course you should try it.”

So he submitted his audition — a simple smartphone video of him playing some Killers songs on guitar — to the band. They liked it, and Connolly flew to Las Vegas to meet with Killers frontman Brandon Flowers. Some rehearsals followed, and within a few months Connolly found himself onstage in Australia playing “Mr. Brightside.”

“I mean, I realistically have a very short list of bands that I would do this for,” Connolly admitted. “So the fact that a band that is on that list, the opportunity came for that, that doesn’t happen very often.”

Expanding his repertoire

Given his audition, and his reputation as a guitarist, Connolly figured he’d be playing a lot of guitar. As their rehearsals progressed, though, it became clear The Killers needed Connolly more on keys. The majority of Connolly’s time with The Killers is spent on synths, organs and other keyboards, with a little guitar sprinkled in.

“If you had told me I would be playing as much keyboards for a band like The Killers someday, I wouldn’t have said yes,” Robbie said while chuckling. “But it is validating. And I take it as a fun opportunity. I’ll be the first to admit I’m not the flashiest piano/keyboard player, but it’s a really fun opportunity to get better and better every day.”

While on the road, Connolly said he spends considerable time writing and recording his own material, turning each hotel room into a makeshift studio. Some of that material will make its way onto his next solo album.

There’s also a good chance those songs come back to Connolly’s other band, Fictionist, which he’s played in for almost a decade. Last May, right after Fictionist’s “Sleep Machine” album release show in downtown Provo, Connolly told his band mates about the possible Killers gig. Connolly said they were excited, and told him to go for it.

“That was a hard one,” he recalled. “I spent nine years figuring out music, touring the country, playing in a band with these guys. They became my best friends. Besides my wife and mom, they know me better than anyone else in the world. It felt nice to know we could push pause on it in such a positive way.

“It felt like a good time to do this,” he continued. “And hopefully me being out with The Killers is beneficial to Fictionist as well.”

The clock is ticking

Things have fallen into place pretty nicely for Connolly this past year. Still, it hasn’t been easy. Connolly recalled a recent mix up, when he arrived at the airport on the wrong day for a flight home to Utah. (His flight departed the day before.) He said he felt devastated. Connolly’s family time is limited these days, and he doesn’t want to miss a moment. Between FaceTime sessions, meet-ups in other states and the occasional Utah visit, the Connollys are piecing together a unique kind of family life.

“In the last few months I’ve really learned to appreciate my time,” he said. “Every hour with my boys is precious time. But it’s making me love every minute. I want to make my time worth it.”

The Killers will tour Europe in February, South America in March and Australia in April/May. From there, it’s back to the U.S., then Europe again, then the U.K., and then some more European dates. The last tour date listed on The Killers’ website is July 24 in Finland. According to Connolly, the shows could likely continue well beyond that.

“So yeah,” he said, “it’s going to be a crazy year.”

If you go …

What: The Killers

When: Tuesday, Feb. 6, 7 p.m.

Where: Vivint Arena, 301 S. Temple

How much: $42-$92

Web: ticketmaster.com