This is so important to understand. Student athletes are asking the coach for a spot on the team and full support through the admissions process…not for a likely letter.
Some accepted athletic recruits never even receive a likely letter due to timing issues.
I don’t have specific knowledge at UPenn in the sport I assume you are talking about, but agree with politeperson that the coach will know if it’s possible and what it takes for acceptance into certain schools. Then, admissions will be the final arbiters of the acceptance and school decision.
Good luck.