Jose Gaya revealed he contracted coronavirus but the Valencia full-back called on Spain's population to think about the elderly and not collapse the healthcare system in an encouraging social media message.
On Sunday, LaLiga side Valencia confirmed five cases of COVID-19 among the first-team players and staff amid the coronavirus pandemic.
Ezequiel Garay was the first LaLiga player to confirm a positive test before Valencia team-mate Eliaquim Mangala followed suit, and Gaya also announced his diagnosis on Sunday.
"I have tested positive for the coronavirus," the 24-year-old Spaniard wrote on Instagram. "I am isolated in my house and totally asymptomatic.
"Therefore, I want to take advantage of this social network so that we do not collapse our healthcare. Now it's the elderly people who need it the most, and it's the serious cases that need to be taken care of by our health heroes.
"I want to thank all members of the Spanish health service - cleaning staff, guards, nurses, doctors, ambulance and laboratory personnel.
"I also can't forget the security forces and all the people making it possible for us to be lacking nothing right now.
"They're the true heroes of this pandemic. Together we will be victorious."
With Spain in lockdown, LaLiga has been postponed for at least the next two rounds of fixtures.
Spain has reported at least 7,800 COVID-19 cases, with more than 290 deaths.
Globally, the death toll has risen to over 6,500 from almost 170,000 cases.