Sounds like your S is a go getter!
Plenty of student-athletes have college jobs where they work 5-10 hours per week, often in the fitness center or athletic offices. There is time for work, especially if they are playing D3. He can use the student career center to help find summer jobs as well.
Teen/young adult males are often in demand for babysitting jobs as well…in my area they are paid $15+/hour, cash. He could also get certified as a referee/umpire, run football skills clinics for younger kids, and/or do private lessons. These are some of the things I have seen our local sporty teens doing during covid.