Would have been a lot of pressure. He's 17. Bringing him in replace Odegaard (and Saka - he was hurt too) is a huge risk. These are world class players You could do damage to his confidence if he doesn't perform well, increased risk of getting clattered by some caveman if he is isolated as the focal point of our attack, and probably lots of other factors one has to consider. You don't take that sort of risk unless you absolutely have to. I'm sure the temptation must have been there, however if we are a serious club, there was probably already a plan for optimally ramping him up into the first team prior to the start of the season. As much as possible you try to stick to that plan. That's what he's talking about when he's saying cement and bricks. There's things the kid has to learn, habits he has to break, ideas he has to imbibe. He's a baller, no doubt. But he needs to learn how to ball with the big boys at the top level consistently. No rush. Him playing often is unlikely to be what truly defines us this season.
And if it is, and it's deserved minutes, I'm extremely happy to be wrong: as this would mean he's earned his way into the first team, and we'll be seeing him do really special stuff as the season goes on. Either way, he's announced himself to the Arsenal fan base, and maybe even some non Arsenal fans are starting to notice. We have a special talent on our hands. Let's enjoy his development.