Marinelli isn't one to wrap his thoughts in candy coating before assessing one of his player's performances, so his blunt critique isn't a shock.
Still, it's notable that the defensive coordinator was comfortable giving a thumbs-down review after just 16 plays -- instead of the generic coach-speak we usually receive.
Pro Football Focus charted Charlton with zero pressures on seven attempts to rush the passer, and he earned no tackles.
For his part, the rookie isn't sweating one short performance.
"You want to play more ... only got to play 15 or 16 plays," Charlton said. "It happens. Coach is protecting me. I do what I need to do and run with it. I got a good burn out there. I got a chance to get my feet wet. So it was a good chance to get out there and play in an NFL game."
Entering the draft, plenty of scouts questioned Charlton's inconsistent play at Michigan, lack of power at the point of attack, and unreliable game speed.
The rookie knows that he will get more chances to prove he can be the Cowboys' answer at pass rusher as the preseason presses on.
"I'm patient," Charlton said. "Coach Marinelli has a plan for me. So I'm patient. I'm going to let everything come to me."