2019 Angels spring training preview: Starting rotation

As the Angels head toward the first workout of spring training on Feb. 13, we are providing breakdowns of how they stand with their roster by position groups. Players acquired this winter include the method of their acquisition in parentheses. Today, the starting rotation:
2018 RECAP
The Angels began the season with a six-man rotation, although more precisely it was a five-man rotation with a sixth starter added occasionally. By the end, they could barely piece together any kind of rotation