MLB Spring Training has arrived and your favorite players are back on the diamond, so prepare for the season with Mariners Spring Training Apparel from our MLB Shop at Fanatics.com. Browse New Era Spring Training Hats that are a must-have with the team's Spring Training Patch emblazoned on the side. Look just like the players with Mariners Spring Training Jerseys from the official MLB Spring Training Jersey collection. We also have a full lineup of Seattle Mariners Spring Training T-Shirts on deck for men, women and youth so every baseball fan can slide into the season in official gear. Order your Seattle Mariners Spring Training Hat or Shirt today.