Pittsburgh Pirates Yellow Crewneck MLB Officially Licensed Replica Jersey T-Shirt. Customized (Any Name / Number on Back of Shirt) or Blank Back. Majestic Shirts are the Official MLB Uniform Top for Youth Little League and Adult Softball and Baseball Leagues. Available in 10 Youth & Adult Sizes. Custom Order Info: If ordering Custom, after you have placed your order please contact us on Amazon through the Contact Seller with the Name & # you’d like on the back of the shirt.