Quite simply, Junior's role models are his friends who are willing to stick up for him (Gordy, Roger, and Penelope) and, most importantly, the mentor who values Junior's true worth: Coach.
First, let's look at the friends who can be seen as Junior's role models. Penelope, who first seems to be only "Penelope the Beautiful" redeems herself on Halloween. Junior finds a new respect for her when she dresses up like a homeless lady in order to collect spare change (instead of candy) for the homeless. In an effort to copy his role model, Junior does the same (because he is also dressed as a homeless person).
In regard to Gordy, Junior looks up to him because he is the "class genius." Junior corrects the teacher in the middle of a lesson and Gordy is willing to stick up for Junior. Gordy's response hurts Junior a little bit:
I didn't do it for you. ... I did it for science.
But this still augments Gordy's intelligence where Junior is concerned. Junior has so much respect for Gordy that Junior is brave enough to request friendship. The two do become friends, the "Indian" and "Gordy the Genius White Boy." Here we have an example where Roger, Penelope AND Gordy come to the rescue. Gordy slams his textbook down and all of them walk out of the classroom to protest the teacher. Mimicking Gordy's humor and sarcasm, Junior laughs and says the following:
I used to think the world was broken down by tribes ... black and white ... Indian and white ... but (now) I know ... the world is only broken into two tribes ... people who are assholes and ... people who are not.
Quite frankly, Roger, Penelope and Gordy are "people who are not" assholes.
Coach is the most important mentor and role model for Junior because he always talks about both respect and dignity. Further, Coach is an ADULT role model, and not just one of Junior's peers. Coach and Junior develop a wonderful mentor/student relationship that Junior treasures. It begins with a compliment from Coach:
[Junior is] the best shooter who'd ever played for [Coach].
Coach says this after he first talks about the importance of "dignity and respect" and follows it up with the first drill of the team: one hundred laps. When most of the students drop out, Junior perseveres. Coach is impressed by Junior's sheer tenacity. Coach also encourages Junior by valuing his opinion. Specifically, Coach even laughs with Junior (encouraging others) when Junior says this:
If these dang Indians had been this organized when I went to school here, maybe I would have had more reasons to stay.
And, of course, one of the biggest shows of concern, compassion, and respect is when Coach visits Junior in the hospital when he is knocked unconscious at the game.
In conclusion, we must say that in speaking about the friends and mentors who have wonderful qualities encouraging Junior, there are other characters who serve as foils. These are characters who hold absolute prejudices against Junior. These are characters like Penelope's father and Mrs. Jeremy (the faculty member who teaches social studies). As readers, we need to put the actions of these negative characters out of our minds so that we can focus on the positive traits of those characters, like Coach, who are truly worthy of praise.