You may have missed it in April.

As Orioles top prospect Jackson Holliday took the field at Fenway Park early in the season to make his big league debut, he did so wearing a small, red-white-and-blue patch with the words “MLB Debut” and the league’s logo on the right sleeve of his road gray jersey.

That exact patch is now affixed to a limited-edition rookie card of Holliday that the 20-year-old phenom has autographed. And, because there was only the one patch, the card is the only one in existence.

Holliday is one of more than 150 players to have an MLB Debut Patch card in this year’s release of Topps Chrome Update, one of the last baseball card products from the 2024 season and available starting today. The featured group of players debuted from June 1, 2023, through May 24, Topps said in a news release.

Colton Cowser, recently named a finalist for American League Rookie of the Year, has one, too. So do young stars Paul Skenes, Elly De La Cruz, Jackson Chourio, Jackson Merrill, Shota Imanaga, Yoshinobu Yamamoto and Wyatt Langford, among others.

Topps started making the patches and cards last season. Because they’re so scarce and unique, they’re highly sought after by collectors. And expensive.

Dave & Adam’s, a sports card store based in Amherst, New York, placed a $150,000 bounty on the patch card featuring New York Yankees shortstop Anthony Volpe in last year’s Update set.

If you miss out on landing Holliday’s six-figure patch card, there are a few other unique offerings in the set worth chasing.

There’s a one-of-one dual autograph card with Holliday and Billy Ripken, the two forever linked in hobby lore after Topps produced some of Holliday’s first rookies as a tribute to Ripken’s infamous “F--- Face” card from 1989.

And there’s a triple autograph card with Holliday and two other Jacksons: Merrill and Chourio, both finalists for National League Rookie of the Year.

2024 Topps Chrome Update, which also features Holliday on the cover, hit shelves Wednesday. Your best chance to land one of these grail cards is to head to your local hobby shop and start ripping packs.