3) Mickey Moniak looks like a legitimate MLB regular
Mickey Moniak played his heart out in Spring Training and had done well enough to earn a role on this team even if he didn't end up winning one. The Angels had their outfield set heading into camp making Moniak's mission of making the Opening Day roster almost impossible, but the young outfielder kept improving in the minors until the Angels simply couldn't keep him there anymore.
Moniak got his shot in mid-May of this season and never looked back. He hit a leadoff home run in his first at-bat in Cleveland. He recorded three hits in four at-bats that day including a walk and two stolen bases. Moniak remained a staple from then on most of the time against righties playing somewhere in the outfield and doing really well.
The 25-year-old has 14 home runs and an .802 OPS heading into the season's final day. He's shown off some really nice speed, incredible defense, and more power than expected as well. Moniak does have to draw more walks and limit more strikeouts offensively, and also has to learn how to hit lefties, but there was so much to like from Moniak who absolutely has a future role on this team.