SCOTTSDALE, Ariz. — When the hiss and whiz of a Wiffle Ball game really start to fly, that classic, plastic yellow bat survives about as long as a Bomb Pop in July. So Nolan Arenado made a phone call.

“I called Old Hickory, the bat company I use, and said: ‘Hey, I play Wiffle Ball with my boys. Can we make some bats?’ ” Arenado said. “Because every other bat we get is terrible. And I actually got my model in a Wiffle Ball bat. It has my name on it.”

Model 28NA-Wiffle. Nolan Arenado.

The bat is just like the 34-ounce, blond-and-black, maple tree trunk he used last season to hit 42 home runs. It is just like the one he’ll use Monday night when the Rockies open their season against the Arizona Diamondbacks in Phoenix. But in miniature.

“It’s awesome,” he said.

Arenado plays Wiffle Ball at the end of every summer for 2½ months. This major-leaguer, he’s still a kid.

For 16 years, the Rockies’ star third baseman, with his brothers and cousins and friends, wage a never-ending, always-rambunctious game of Wiffle Ball in Lake Forest, Calif. The game is always the same, now and forever. They just have to wait until after the 162-game major-league season.

“It’s what we do. We go play Wiffle Ball,” Arenado said.

He is 24 now and about to start a fourth big-league season. He was 8 when the Wiffle Ball game started.

When each regular season ends, Arenado said he is usually angry that it’s done “because we didn’t go to the playoffs and baseball is over,” he said. “So the only thing I look forward to is Wiffle Ball.”

The rules of this Wiffle Ball game are simple.

“Can’t throw your hardest. Other than that, most anything goes,” Arenado said.

Standard ghost-runner rules apply if the bases are loaded. And they use the dotted Wiffle Ball rather than the slotted kind, to avoid wild, darting pitches. Also, they can throw the ball at a runner to force him out, but not at first base — fielders have to throw across the diamond. And there’s a basketball-style possession arrow to help resolve arguments. If they can’t agree on a call, it’s settled by alternating sides.

“If you saw our fights back in the day, you’d understand why we changed that rule,” Arenado said. “Now there are less arguments. More talking trash, but less fistfights. Games actually finish now. Back then, there would be fights happening and games would be done before they finish. We’d argue everything — someone’s cheating, a safe or out call, whatever.”

There are two teams. The first team, made up of professionals, is required to hit left-handed. The other three don’t play pro ball.

The Pros — Nolan Arenado, Rockies third baseman; Jonah Arenado, brother, San Francisco Giants third-base prospect; Josh Fuentes, cousin, Rockies third-base prospect.

Vs. The Bros — Justin Fuentes, cousin; Alex Luaces, cousin; Gerardo Arenado, cousin.

And occasional call-ups — Cousy Arenado, Nolan’s brother, who now lives in Los Angeles, so he doesn’t play all the time; Carlos Rodriguez, everybody’s friend.

Sometimes they play in the backyard of Arenado’s parents’ house or in the outfield at El Toro High School so they can use the fences. Usually the game is at a greenbelt nearby.

“There’s a park that’s good and the lights turn off at 9, so we usually like to start at 7,” Arenado said.

People walk by and don’t notice the three-time Gold Glove winner. They’re just kids.

When Arenado was a 19-year-old Rockies minor-league prospect playing for Single-A Modesto, the team swung through on a road trip about an hour north of Lake Forest.

“I was playing in Rancho Cucamonga, and I drove home with my cousins. We were like, ‘Dude, let’s just go play,’ ” Arenado said.

“We played Wiffle Ball until like 3 in the morning. We drove behind an L.A. Fitness, because that was the only place we could find and there were little lights. But we turned the car lights on to play.

“I had a game the next day too, and I went like 0-for-4. It was a bad game. But I raked in Wiffle Ball, so it was cool.”

Awards are issued at the end of every Wiffle season. Justin was the Cy Young winner last season and Josh won a Gold Glove. Alex finished second in MVP voting.

“He rakes in the beginning, but then he blows it,” Arenado said. “He gets cold every year. He gets figured out.”

Last season’s MVP?

“Oh, me,” Arenado said. “They know it. Write it down. Every year. MVP: Wiffle Ball, Nolan.”

Since Arenado’s rookie year in 2013, the Rockies have yet to play meaningful games in September. He has never played in the playoffs. If one day the Rockies and their star third baseman reach the postseason, it will only delay the Wiffle Ball game.

That’s why a plastic yellow bat will never work. The game will survive as long as the Old Hickory model 28NA-Wiffle will allow.

“I can’t imagine ever stopping that game,” Arenado said.

“We love doing it. We talk about it all the time. The guys who don’t play can’t wait for us to get home to play. We all love baseball. We love watching the game and talking about the game, arguing about different players.

“Oh, and make sure you put this in the article,” Arenado said. “I win the Triple Crown every year.”

Nick Groke: @nickgroke or ngroke@denverpost.com