As Kieran Kelly stood behind home plate at Charles Schwab Field on Sunday and sang the national anthem to thousands of people, he had fresh scratches on his arm.

The bright red scratches were courtesy of some bushes in his parents’ Dundee backyard and a Wiffle ball game between brothers.

“There’s unfinished business in that field,” Kieran said. “And it’s still unfinished.”

From 2009 to 2018, the four Kelly brothers created and hosted the Dundee Classic Wiffle ball tournament in their parents’ backyard.

At its peak, the tournament had 21 teams, some comprised of former college baseball players, and attracted spectators like Nebraska Gov. Pete Ricketts.

The Kellys kept statistics, handed out trophies, made highlight videos and gradually stomped the grass in the backyard into dust.

The batter’s box was two old car mats laid where the hitters stand. Hostas guarded the left field fence. And the dreaded bush in center field.

“As a dad, I look at this and think, ‘What better use of a neighborhood backyard than this?’” Joe Kelly, the boys’ father, told the World-Herald in 2016. “It’s 100 friends over on a Saturday.”

That tournament was where Kieran sang the national anthem to a crowd for the first time. He was so nervous about singing, Kieran said he struck out the next five times he was at bat.

“Yeah, we all remember that,” a brother quickly responded when Kieran told the story over a conference call last week.

“So now the stage is slightly bigger,” Kieran said before singing Sunday. “The lights are slightly brighter. The words are the same, luckily. I don’t think those have changed.”

The brothers had to end the Wiffle ball tournament in 2018 when military obligations got in the way for two of them. Three of the four brothers are in the military.

Rory, the oldest, is a major in the Marines and lives in Indiana. Henry is a lieutenant in the United States Coast Guard and lives in Maryland. Kieran is in the Navy and currently lives in Miami. The youngest, Brian, is a musician who lives in Nashville.

All three brothers came back to Omaha to not only watch Kieran sing, but to watch his promotion. About an hour before he sang the national anthem, the Kelly family and friends stood in front of The Road to Omaha sculpture as Henry promoted Kieran to naval lieutenant.

As Henry read from a script, the crowd slowly grew as CWS fans stopped to watch and cheered at the end. One person chanted “USA.”

Then Kieran went inside the stadium to get ready to sing.

During a phone call last week, the brothers joked about their Wiffle ball talents but got serious when talking about how proud they are of each other and specifically Kieran’s promotion.

“A promotion especially to this rank, lieutenant, is no easy task for an officer,” Henry said. “There are numerous officers that do not make this rank. Only those officers that exemplify the utmost leadership, hard work, ethics and teamwork essentially are selected for promotion.”

Kieran auditioned to sing the anthem months ago, but as luck would have it, he ended up singing at the game featuring his — and half his family’s — alma mater, Notre Dame.

But before heading to the College World Series, the brothers had other business in their parents’ backyard on Saturday. Before their tournament morphed into a multi-team spectacle, it started with four brothers splitting into two teams.

“We’d play for hours and hours,” Brian said.

“There are too many scars on my body to not go out in the backyard this weekend,” Kieran said. “I remember every odd fence post and plant that has really made us into the men we are today.”

Before their game, Henry had plans to prove he was the greatest of all time. Brian said he looked forward to seeing how everyone else’s skills have waned but stopped short of trash talking his three older brothers who, unlike him, have undergone military training.

And after the game?

“The competition is still there,” Brian said.

“Some skills, too.”