The Orioles promoted Hays to the major leagues on September 5, 2017, making him the first 2016 draftee to reach the major leagues. He made his major league debut September 7, 2017. He had his first MLB hit, followed by his first MLB home run, in a 9–3 loss against the New York Yankees on September 16. In 20 games for Baltimore during the 2017 season, he batted .217/.238/.317 in 60 at bats.

This September 6, 2017 Baltimore Orioles ticket was signed in black by Hays. The Orioles were rained out on the 6th, but these tickets were used for entry on the 7th. This item includes a Great Moments COA.