Players must expect a "significant reduction" in prize money when tennis tours resume, Feliciano Lopez says.
Lopez, a seven-time winner on the ATP Tour and tournament director of the Madrid Open, thinks prize funds will also be severely affected next season.
"The companies and the sponsors, they might have to fire employees," he said.
"This is happening everywhere in the world so the first thing they cut is sponsorship, and this is going to be affecting tennis massively.
Lopez, who should have been preparing to defend his Fever-Tree Championships title at Queen's Club from Monday, added: "We have to understand that tennis is not going to be the same, at least for one, two, three years. I don't know how long.
"But we need to survive this moment and we need to be united.
"The players need to understand that it's going to be a significant reduction in the prize money. I see now the scenario where tournaments will survive with a significant reduction in prize money - not only for this year, but also for (the) 2021 season."
The ATP Tour is currently suspended until 1 August, but a schedule for the late summer and early autumn is expected to be published this week.
The US Open is likely to go ahead in New York from 31 August, despite the strong reservations of players such as Novak Djokovic, Rafael Nadal, Nick Kyrgios and Simona Halep.
"I personally would go and play the US Open: I think the majority of players would also do the same," Lopez said.
"I think the US Open know there might be many players that don't want to go and play there.
"But I think the US Open is not depending on only the top players playing. My personal opinion is that they are planning to have the event thinking that some of the top players - I don't know how many - might not play."
Lopez added he was "confident" the Madrid Open would be be able to go ahead in mid-September with a crowd capacity of between 30 and 40%.