NFTs are growing in the baseball world, with Major League Baseball announcing a long-term agreement with digital collectible company Candy Digital on Tuesday -- headlined by a one-of-a-kind Lou Gehrig NFT that will be released on July 4.

NFTs, or non-fungible tokens, are digital assets representing real-world objects, like a piece of artwork, or music … or a baseball card. They're tied to a blockchain (MLB and Candy's NFTs will run on the Ethereum blockchain), and are essentially certified to be unique.

For Major League Baseball, expanding into the booming NFT market -- the most expensive NFTs have sold for millions of dollars -- means creating a whole new type of collectibles fans will be able to buy, trade and share.

The first NFT from MLB and Candy is a 1-of-1 NFT of Gehrig's iconic "Luckiest Man" speech that the Yankees legend delivered on July 4, 1939, at Yankee Stadium, after being diagnosed with ALS. The Gehrig NFT will be released July 4th weekend, and proceeds from the sale will support ALS charities.

MLB will celebrate the first Lou Gehrig Day on Wednesday.

"From trading cards to autographed balls, baseball fans have demonstrated their passion for the sport and its players through collectibles for decades," MLB Commissioner Rob Manfred said in a statement Tuesday. "In working with Candy Digital to offer NFTs to MLB fans, we’re delivering an exciting new addition to the robust baseball collectible market. The founders of Candy are a dynamic group of executives with an impressive track record. We’re excited to be the first partner in this new venture with a team uniquely positioned for success."

MLB already produces trading card NFTs in partnership with Topps, but now with Candy there will be a wider range of baseball digital collectibles -- for example, memorabilia-style NFTs, or baseball card-style NFTs, or artwork-style NFTs portraying big moments on the field, or NFTs of highlight plays. Following the Gehrig "Luckiest Man" NFT, more are expected to be rolled out.

Candy Digital is a joint venture being launched by Fanatics chairman Michael Rubin -- Fanatics already sells MLB jerseys, clothing, collectibles and more -- Galaxy Digital CEO Mike Novogratz and entrepreneur Gary Vaynerchuk.

"At its core, Candy is about allowing everyone to own a piece of their passion -- whether that be sports or gaming, fashion or art, music or pop culture, the goal is to broaden the fanbase of digital collectibles," Rubin said in a statement. "Both Candy and our pioneering partner Major League Baseball live at the intersection of passion, community, innovation, and digital transformation -- the sweet spot."

On Candy's platform, fans will be able to purchase, collect, view and trade the NFTs, which will be developed by their team of digital artists, designers and technologists, starting with the world of sports.

"As a lifetime collector myself, I couldn’t be more excited for what this partnership means for both creators and consumers," Vaynerchuk said in a statement, "especially the uber-passionate MLB community who craves collectibles and celebrating the iconic moments that makes this game so special."