You do want to get backups some reps to prepare in case there is a freak injury. And you are smart to do it at times for the benefit of the the starter's health.
When your star sophomore was tanking and dragging down the team, that was a good time to put Vedral in. Not only were his miscues preventable, Martinez was taking brutal hits from bad choices. We probably could have won at least two more games. But we waited for Martinez to finally get broken from making repeated bad decisions. You do not leave a guy out there when he is floundering. This is already known to be a game where making one mistake can cost your long term health.
Obviously the staff knows more about the capabilities of the individuals on this roster than do you or I.
I’ll leave it at that.