MLB rookies to wear 'MLB Debut' patches on Opening Day that will be turned into Topps cards
Why are some MLB players wearing debut patches - The Washington Post
SBJ Morning Buzz: Miami Marlins make ADT jersey patch sponsor
MLB players to wear official debut uniform patches - ESPN
Fanatics Collectibles, MLB, MLB Players Inc. Unveil First-Ever Memorabilia Patch Created Specifically for Trading Cards — Fanatics Inc
Rookies To Wear “NFL PREM1ERE” Patch To Commemorate First Game – SportsLogos.Net News
Unless I'm missing something, this seems like more Fanatics bull$hit. Cut up some unsold retail jerseys and pretend they're special : r/baseballcards
MLB debut players will have special patches on jerseys : NPR
Red Rose Sports Cards
Former Maverick Kyle Leahy makes MLB Debut