Why did Auckland City's goalkeeper play without a main sponsor on his jersey?

Why did Auckland City's goalkeeper play without a main sponsor on his jersey?

Nathan Garrow played against Benfica and Boca Juniors without the Michelob Ultra beer sponsorship due to his age and US laws.

At 20 years old, and with the legal drinking age in the tournament's host country (USA) being 21, alcohol promotion laws state: "Advertisements should not show people under 21 consuming alcohol."

Garrow is the only underage player in Auckland City's squad, which prevented him from advertising Michelob Ultra at the Club World Cup. However, in matches played in New Zealand like the OFC Champions League, he could display the sponsor since the legal drinking age there is 18.