Hi,
I believe logic should be altered for using players set to a SP role when the available relievers have been exhausted.
https://www.whatifsports.com/HBD/Pages/Popups/Boxscore.aspx?gid=77983125&tab=box&mode=modern
The sim used a SP that it probably ID'ed as the best option among the SPs, but ignored stamina. Elcano had just started the previous game, whereas at least 2 other SPs were at 100% and were passed over.