Revealing mistake: In the scene where Pedro sticks a cigarette in Jobu's mouth, he lights it and it starts burning on its own. There's no way a cigarette can burn like that without being inhaled. (00:18:25)
Revealing mistake: In the celebration scene at the end, there are multiple times when you see huge sections of the stadium with no people in them. The most obvious is when WMH jumps into Jake's arms. (01:39:05)
Answer: He just shows up, uninvited. When he arrives, they can't find his name on the list; he's later (comedically) removed from camp in the middle of the night when security carries him out on his bed (while commenting, "This is the guy who wasn't invited to camp"). So, he's relying on his speed and charm to get him a spot on the team... which, of course, ultimately works.