Complex sentence: Miguel, had transferred from CPHS to TAFT to play High School soccer but instead ended up playing High School football, his dorsal number was 52 which is why Miguel was also knows as "B52" during his football season at TAFT High School.
Split into simpler sentences: Miguel, had transferred from CPHS to TAFT to play High School soccer but instead ended up playing High School football, his dorsal number was 52. Miguel also became knows as "B52" during his football season at TAFT High School.