It had been expected that the Pro12 champions would invest in the summer, but Humphreys has revealed that they will not strengthen.
"We would love to spend in the summer but there is no money," he told BBC Sport.
"There is no money at all for us and that comes from factors like having the least funding of anybody. Therefore, there is no money left to go and strengthen."
Ospreys have won the Pro12 tournament four times.