Great call as he and the others were in the crowd cheering him on.
An additional scene with Freddie at any point in the middle of the film would have made for a nice bridge from all we know in his opening scenes to him being at the tournament and cheering on Daniel. Since they did live in the same area, it makes sense that they would have seen each other (or school) and still interacted at any point prior to the December tournament. That was a good 3-4 months of time! They had to have hung out, talked, etc.
Seems like Freddie being at the tournament is motivated by he and his friends wanting to see a good fight and for Johnny to go down. And Freddie remembers the beach confrontation as well since he was there.
"what's this? A doorknob? Good show!" the easily impressed Dr. Bartley

Daniel's so called friends came back at the end to watch the tournament and are in the audience in the background cheering for him. You can clearly see it in a bluray or HD version of the film.

you are absolutely correct.

It's an animal kingdom

The kid that gets his ass kicked loses his reputation and gets shunned. That's just how it is in high school some times.

they are actually in the soccer scene of daniels first day of school and they diss him.

Exactly! That's why I always change the channel when that scene comes on. It wasn't like Daniel antagonized the situation. The bullies started it, and on top of that, from what I rememberhe got jumped and they kicked him while he was down literally.
I can tell that the freind felt remorse for Daniel and wanted to help him but like you mentioned, he succumbed to the peer pressure.
But you mention some good points, Daniel took a heck of a beating and did not back down until he physically unable to.so I don't think that was realistic that the other guys did not want anything to do with him.

Sadly it never did, he was never mentioned or seen again after the beach scene.
He buckled under the pressure from his friends about being friends with someone who was perceived as weak or uncool.
What I never got was how they could think that? Daniel didn't take any of Johnny's crap and even landed a punch so in any other social situation he would have gotten major points from his friends for not backing down. It just never rang true to me that he would be scoffed at.