Before you send me a DM on Twitter, exclaiming that Yankees outfielder Mike Tauchman is not a rookie, I implore you to fully digest the letter of the law according to the Major League Baseball rule book.
According to MLB rules, for a player to be eligible for Rookie of the Year honors, there are two stipulations which must be adhered to in any previous season.
The first is that said player must not have exceeded 130 at-bats, or 50 innings pitched in the majors. Second, the player could not have accumulated more than 45 days on an active roster or during the period of the 25-player limit (excluding time spent on the injured list).