Episodic Middle

[Gammer]

I was planning out the middle portion of my story, and realized that only like three or four of the chapter moved the actual plot along. Everything else was very episodic and a lot the chapters felt like one-shots.

But I feel they were necessary because the MC is learning how to fight, be a warrior and learning about the magic of the world. So the chapters are basically the equivalent of the RPG Side-Quest to level up your character and gain more experience. Plus I really wanted to avoid the whole "instant expert" cliche that fills the fantasy genre and really go into what the MC has to go through both mentally and physically to get up to speed with other more experienced characters.

So is there any way to hook the heroes warrior journey into the main plot?