A game-worn Babe Ruth jersey is expected to become the highest-priced piece of sports memorabilia ever sold when it hits a Yankee Stadium auction this Saturday.

Valued at approximately $4.5 million by SGC, a card-grading and jersey authentication service, the jersey is apparently one of just a handful of its kind that remain in existence, complete with the original "Yankees" team name across the front and "Ruth" stitched on the inside of the collar. Dating back to the 1920s, it grades out in "excellent/superior" condition thanks to analysis from SGC's Dave Grob, who authenticated a Ruth road jersey that went for more than $4.4 million, the current memorabilia record, in 2012.

"This Babe Ruth jersey may prove to be the most valuable piece of sports memorabilia ever," SGC CEO Dave Forman said in a release on the game-worn item.

The private collection from which the jersey came was largely unknown to the public before an announcement of the auction in 2018, per SGC. It will appear alongside hundreds of other Ruth-related items, including cleats, contracts, photos, trophies, baseballs and his personal check ledger, at Yankee Stadium as part of the memorabilia sale, hosted by Hunt Auctions. Many of the other items were consigned by the Sultan of Swat's own family.

Its authentication and approximate $4.5 million valuation comes just over a month after a 1916 Babe Ruth rookie card, featuring the slugger with the Boston Red Sox, sold for $130,000 after being discovered in an old piano.