An all-too-common situation:
John Smith is a long shot for landing on an NFL roster during or after the Draft (as an Undrafted Free Agent), but finds an agent that's willing to pay for training, so he leaves school (with only one semester left before he graduates) to train.
He gets picked up and gets cut (if he made it to training camp at all), now he has nothing.
The couple grand he got as a signing bonus is long gone.
Listen, I understand that playing in the NFL is a once in a lifetime opportunity. But if you're that close to getting your degree, I'd strongly consider training at school, unless your school doesn't have the staff, facilities, and equipment necessary for you to train adaquately.
So many guys in this situation end up broke after a few years of trying to get back in the NFL, only to look up and they're 27/28 years old, trying to scrap up the money they need to pay for their last semester of classes so they can get their degree.
So again, it's your life, so do what you want. I'm just offering my two cents.
Have a great weekend.