I met him at BayCare Ballpark in Clearwater, Florida, in 2025 when the Pittsburgh Pirates, for whom he was a coach, came to play the Philadelphia Phillies in the spring breakout game.
Kieran signed a 2021 Greensboro Grasshoppers Team Set card #20.
https://www.baseball-reference.com/register/player.fcgi?id=mattis001kie