I agree but Martinelli was out for months and Arteta threw him on the first 2/3 matches he was available then binned him. He went off injured against Chelsea iirc and then he was back. He wasn't performing lost his confidence and Arteta used that protecting players line.
Arteta reckless with the young boys when he's desperate.
I do worry for Saka under Arteta. He's played too much ball and it has shown the early part of the season minus the Spurs game but seems to have come into form over the last couple of games. The over reliance on the young players is down to the experience players going missing minus Laca so he has no other choice but to over play them.
Also if we really think about it what coaches do you actually trust with younger players nowadays? They all over play the good ones minus Pep and he's really only had Foden to look after. Plus he has the squad where he doesn't require Foden to play week in week out when he was developing. Look at Pedri played a million games in the year for both Barca and Spain and then picked up a muscular injury that has kept him out for as few months. Wenger was reckless with Wilshere.
I think the unbeaten run didn't help Martinelli get minutes. As we known majority of coaches prefer to bring on experienced and defensive players to hold a lead. And I think it was only the Palace game where you had to chase the game in that run. Also factor in ESR form on the left was far better than expected and iirc Martinelli is regarded to be a LW by the club.