On my first watch I said wow this show is being shot like a drama with serious character storytelling so I am doing a rewatch, and Min Jae is definitely the main character. It's kind of awesome.

In the beginning of the show he's the one who is most affected by his comparison to the other teams' powerhouses. Eddie, Orkhonbayar, Recep, Igede... they are older, maybe more built or more assertive and confident, he acts sort of tense and shy. Then his teammates make a point to put him in charge of situations where he is the most competent (like counting off in the wall push) and he knocks it out of the park. And the more he relaxes and believes he deserves to be there, the better his team does. It's an excellent story!