It just feels like that a lot of people are forgetting that he's primarily the coach of the "Esperion Youth D1 Team" and this is essentially the D2 team. While he has control over the D2 team, he's not the coach; Nozomi is. In that sense he can't necessarily coach Aoi minutely and can only give him information based on when he's there. He's placing his faith in Nozomi to be able to relay what he wants Aoi to become. The coaching dynamics for the manga is quite nice to read, albeit there are some tropes.
@Petrichormus
They're not limited to their own positions for play-making, so it doesn't feel that what it feels like he's aiming for.
My opinion is that Fukuda wants Aoi to be the catalyst for the team to play aggressively through using his wide vision (and/or play to Esperion's style of football). There are some subtle hints at foreshadowing, especially with the hints of comparing Aoi to the Mushashino captain; he's able to direct traffic for the entire team (even Kaneda, who everybody else doesn't get along with). Aoi's getting there, but there are still some hurdles he's working through so that he can earn the other player's trust.
Basically, how can you attack confidently if you don't believe there aren't any weaknesses behind you? If Aoi isn't defensively able to cover his position how can I trust him to attack? etc. etc.