Christian Pulisic’s calf injury is the USMNT’s biggest story at the World Cup. Here’s what to know.

IRVINE, Calif. — In the traditional American sports, there are rules requiring teams to publish injury reports.

Sure, a coach might just say a player has a “lower-body injury,” especially in hockey. But there still are rules, and many Philadelphians (especially 76ers fans) might know them by heart these days.

At the World Cup, there are no rules — and there’s even less incentive to tell the truth. There’s a long history of subterfuge, from Brazil’s Ronaldo in 1998 to Canadian star Alphonso Davies’ hamstring and U.S. star Christian Pulisic’s calf today.

So if you’re wondering why the U.S. staff haven’t said much about the matter, the answer is simple: why should they? All it would do is give things away to the tournament’s other teams, including the Americans’ next opponent, Australia.

“When I’m in England, they tell you exactly what it is with stuff like this,” said midfielder Brenden Aaronson, whose Medford and Union roots make him as well-versed in American ways as the world’s game. “With this situation, I can’t tell you what it is because I’m not a part of the medical staff and stuff like that. But it is different, and it is a different part of the game when it’s at club and in international football.”

Officially, Pulisic remains day to day. He trained on his own during the first 15 minutes of Wednesday’s practice, which was the portion that was open to watch. Most of that time was spent in the team’s workout tent, but he emerged toward the end and walked across a field to kick a ball back and forth with a coach.

» READ MORE: A USMNT history lesson is a reminder: The win over Paraguay was big, but it was only one game

This was the extent of the day’s drama, even though Pulisic’s absence from Friday’s game (3 p.m., Fox29, Telemundo 62) obviously would be a huge deal.

What do Pulisic’s teammates think of all this? Everyone who has spoken this week hasn’t said much, and that continued Wednesday.

“I’m not sure the exact sort of terminology of his injury,” defender Antonee Robinson said. “I mean, he’s been taking it day by day, and he’s not been training fully with the group yet. We’ve still got a couple of days to see where he’s at, and thankfully we’ve got a lot of boys on the bench who are eager and ready to get involved in helping the team, and a lot of quality.”

» READ MORE: As the USMNT returns to work at the World Cup, Australia’s big win sharpens the focus

A few hours later, the caravan flew north to Seattle to get ready for Friday’s big game (3 p.m., Fox29, Telemundo 62). The U.S. will train at the University of Washington on Thursday, then get ready for a thunderous atmosphere at the stadium downtown on Friday.

Along the way, the ritual likely will be repeated: questions about Pulisic, vague answers, and a collective shrug. This is how it is, and how it has been, and it’s just another part of the World Cup’s spectacle.

Speaking of spectacle, they don’t come any better than Lionel Messi’s dazzling hat trick in Argentina’s 3-0 win over Algeria. The 38-year-old tied the World Cup’s scoring record with his 16th goal in the tournament, sending a jam-packed crowd in Kansas City into rapture — and the rest of the world, too.

“For the fans watching, obviously Messi’s probably the greatest footballer who’s ever lived, and he’s still going, still showing quality,” Robinson said. “As a fan, I’m sure it was amazing to watch him. That’s the magic of the tournament: you want to see the world’s best doing what they do on this stage, and hopefully every game like that keeps giving those moments, and it’s enjoyable the whole way through.”

» READ MORE: The USMNT-Paraguay game was the most-watched soccer broadcast in U.S. history

Aaronson has also watched Messi plenty, including in person last year at Subaru Park when Inter Miami visited the Union. He admitted that “the fanboy comes out of all of us,” even though he also knows that if the U.S. finishes second in its group and reaches the round of 16, it could play Argentina.

“If we do play Argentina, we’ll all be ready to go,” Aaronson said.

Messi’s next chance to break the scoring record, which has stood since Germany’s Miroslav Klose set it in 2002, will come Monday against Austria in Arlington, Texas.

But he isn’t the only player chasing history at this World Cup. France’s Kylian Mbappé’s two goals against Senegal on Tuesday took his tournament total to 14, and made him his country’s record scorer with 58 all-time.

» READ MORE: Mark Franek quit being a lawyer to teach the history of U.S. soccer to the future of U.S. soccer in the Philly area

Mbappé’s next game is in Philadelphia, on Monday against Iraq. And if there wasn’t already enough hype around Les Bleus’ visit, their 3-1 win in the Meadowlands raises the hype around what might be this World Cup’s most star-studded squad.

Mbappé and Messi’s heroics were expected to draw big TV audiences, along with Norway star Erling Haaland’s two goals in his World Cup debut, a 4-1 win over Iraq. It was quite a sight to have all three stars play on the same day.

Expect another big number for Cristiano Ronaldo’s debut in the tournament with Portugal, in Wednesday’s 1-1 upset tie with the Democratic Republic of Congo. That game joined Cape Verde’s tie with Spain (featuring former Union midfielder Jamiro Monteiro), Jordan’s hard-fought loss to Austria, and Curaçao’s goal against Germany as great moments by underdogs so far.

“You see the results in the last couple of days, of teams who definitely weren’t the favorites managing to get points, and I think that’s what the World Cup’s about,” Robinson said. “It’s about bringing lots of different cultures together and giving them moments like this, and experiences, and it’s really nice to see.”

The World Cup in Philly

Nine nations will compete in five group stage matches this summer, plus two more in a knockout game on July 4. Here’s what you need to know about those countries — and what those fans need to know about Philly. Click here for more.