It all depends on their eligibility status. A 2.3 guy may be eligible from the opening of recruiting, while a 2.8 guy may remain ineligible throughout the recruiting process, and not be able to play the next season.
At the beginning of recruiting you can look at the HS GPA and guess which players may qualify during the recruiting process.
The higher the GPA, the better the chance to still qualify.
A 2.9 guy that begins ineligible has a decent chance at qualifying during recruiting.
While a 2.0 ineligible almost has no chance to qualify during recruiting.