Diaz, known as "Cashflow" in the boxing world, has made a name for himself in the bantamweight division. He's won all 13 of his professional fights so far. Just this September, he beat Mario Hernandez at Madison Square Garden in a unanimous decision.
The arrest happened when police got an alert about a stolen car. They stopped Diaz and discovered the gun. He ended up in Clark County jail, facing two felony charges. The judge set his bail at $10,000.
This isn't just a small problem for Diaz. Each charge could land him in prison for up to 5 years. He'll likely have to pay a lot of money in fines too. It's a big deal in the boxing world, where people care about how fighters act outside the ring.
Before all this happened, people thought Diaz might fight for a world title soon. Now, no one's sure what will happen to his career. He might lose his boxing license or find it hard to get fights.
Diaz has gone from celebrating a big win at Madison Square Garden to sitting in a jail cell in just a few months. It's a stark reminder of how quickly things can change, even for a rising star in the boxing world.