In Pokémon Sword and Shield, Piers is the only Gym Leader absent from the Gym Challenge's opening ceremony in Motostoke. He makes his first appearance once the player clears the Spikemuth Gym Challenge, where it is revealed that the Team Yell Grunts are actually Spikemuth Gym Trainers in disguise, and that their leader is Piers. Spikemuth is the only Gym in Galar not built over a Power Spot; previously, Chairman Rose had asked Piers to relocate his Gym to a faraway Power Spot, but Piers refused and opted to be the only Gym Leader not to use Dynamax. After the player defeats Piers, Marnie approaches him for her turn at the Gym Challenge. Their conversation reveals that Piers had previously planned to retire as Gym Leader after the Champion Cup ended and planned to pass down the role to his little sister. However, Marnie refused the offer, stating that she could not be a Gym Leader if she succeeds in becoming Champion.
After the player defeats Marnie in the Champion Cup Semifinals in Wyndon, Piers rededicates Team Yell to cheering on the player instead. He and Team Yell assist the player and Hop in accessing Rose Tower by helping them find the Macro Cosmos's League staff hiding the monorail key needed to reach the tower.
Piers plays a vital role in helping to stop the Dynamax Pokémon created by Sordward and Shielbert. He accompanies the player and Hop to all the stadiums in Galar to help their Gym Leaders defeat the Dynamax Pokémon. After the player captures ZacianSw/ZamazentaSh, Piers gives them his rare League Card and returns to Spikemuth, where he can be found giving a concert to the members of Team Yell. He can also appear as an opponent in the player's Champion Cup rematches.
"Spikemuth lacks a Power Spot that would allow Pokémon to Dynamax, and thus not many fans come to visit the town. Piers feels responsible for allowing his town to fall into obscurity and dilapidation. Once in battle, Piers tends to get riled up and will often reveal his strategy early on, but he has the strength and skill to triumph regardless. However, his true passions are singing and song writing, and his talents in these fields are well-known. As such, he currently hopes that his younger sister will take over as Gym Leader."
Rare League Card
"Here are some words from Piers when he first became the Gym Leader of Spikemuth. "Uh... ... ... The name's Piers. It's too bad we can't Dynamax our Pokémon in Spikemuth, but you could say we have a more authentic style of Pokémon battles. And I plan on showin' that off. And well... I have a younger sister, and she's got way more talent than me. But until she's old enough to become Gym Leader, I'll keep rockin' with my crew and make sure Spikemuth stays lively!""
When Marnie was five, Piers caught this Morpeko as a present to his little sister, which eventually became her starter Pokémon. According to her League Card, Marnie's Morpeko helped her become less of a crybaby and more cheerful and outgoing.