If the organization is a registered 501(c)(3), meaning it is a qualifying charitable organization and not just a non-profit, you would be able to take some expenses as a charitable donation.
You should ask if they qualify. If so, you could deduct out-of-pocket expenses for which they would give you a receipt, as charitable donations. You cannot deduct anything that he purchased but did not give to the club, meaning he could not deduct equipment if he kept it himself at the end of season.
