I'm not entirely sure how or why it happened, but I skipped past Trey's Orioles/MLB debut in late September of 2016 when writing my posts at the time. I would speculate that it was a combination of his unexpectedly late end of season call-up, well after the beginning of September when you expect to see guys come up from the minors, and my aforementioned disorganized autograph scans.
After being selected by the Orioles in the 8th round of the 2013 draft out of Notre Dame, Trey steadily rose through the Orioles minor league system, and played at every level from the short season Aberdeen Ironbirds all the way up through the AAA Norfolk Tides. Due in part to his continued ascension, he wasn't included in all of the minor league team sets so he didn't have as many cards as many of his fellow minor leaguers. Neither was he considered a can't miss prospect so Topps skipped him over with their minor league offerings. This led to a smaller number of cards for me to attempt to get signed, which only added to my issues with this post.
As you can see at this point in this post, in addition to help from my dad with his 2016 Mancini Old Man Cards, I discovered more than enough Trey Mancini autographs throughout my disorganized card boxes and scans. Trey was always a nice guy and willing signer throughout his minor league years, so I never had an issue with him signing, just with my having anything for him to sign.
After playing in five games with the Orioles at the tail-end of the 2016 season, and hitting three homers over fourteen at-bats during that time, Trey began the 2017 season as the Orioles everyday left-fielder. As a career first-baseman, he didn't miss a beat during the conversion to the outfield during Spring Training in 2017 and came in third in the American League Rookie of the Year race behind Aaron Judge and Andrew Benintendi. Not bad for a guy who was never considered a top prospect!