Rees-Zammit suffered a foot injury in his fourth game for the Bears, but proved his ability to earn selection on Wales’ bench.
That led to a lot of pre-match study focused on a substitute and he got some of the biggest cheers of the afternoon.
Wales may have suffered a heavy loss, but the winger was still able to reflect on his “happy place” in a social media post.
“It was a great experience,” he said. “I really miss playing in the main stadium in front of our fans.
“It’s unbelievable. You don’t really know you’re left until you come back. When I came and heard most of the crowd.
Wales have won just one of 19 tests while Rees-Zammit is out of the American picture, but the winger is confident of better times under Tandy.
“You’ll see glimpses over the weekend of what’s to come. That’s building a foundation of where we want to be and what we want to be,” he said.
“We can do our best in training, but we have to show it at the weekend when all the fans have paid good money to watch us play. This is what they deserve.”
Rees-Zammit’s last international was against Georgia at the 2023 World Cup and he will aim to help Wales repeat a crucial World Cup performance in December.
Jondie Jones’ brave flowers last to go 12th in the world rankings if the odds are upset in Cardiff.
Rees-Zammit said: “Everyone is locked into what’s next. Japan is going to be a tough game, but everyone is coming away and buying 100%. We’re all ready.”