The Houston Astros made a statement during the 2014 and 2015 seasons that they were not going to start the season with their stud prospects on the active roster. They set what was supposed to be a precedent where they waited until late April 2014 for George Springer and June 2015 with Carlos Correa. With the Astros operation procedures for how to handle saving service time, there was zero chance that 2014 second round pick A.J. Reed would start the season with the Astros.
Look at how the Chicago Cubs handled Kris Bryant last season, and they kept him in the minors for the minimum time they could to delay becoming arbitration eligible for one year, which was about a matter of 14 days or so.