There's no reason he can't get those innings at the big league level. You want to give him time to pitch and have to make some adjustments. Calling him up for a couple starts in September may not be enough.
I’m just thinking that if he gets rocked early in starts he is more likely to get pulled early. Even with this sinking ship of a team. Also command seems his only issue. He threw only 45 strikes in 75 pitches last outing. If it was me I would want to see better before promoting him. It’s not about appeasing the fans. I’m sure he will get a few starts this year. Just a matter of when