Mets prospect P.J. Conlon came up for a cup of coffee in 2018, and this ball was used in his career debut against the Cincinnati Reds. He made history as the first MLB player born in Northern Ireland, and the first major leaguer from Ireland since 1945. Conlon recorded a strikeout and allowed 3 runs before his exit in the 4th inning. The Mets won over the Reds on the road, 7-6.
( C ) New York Mets (photo by Heritage Werks)