Five players in Spain's top two divisions have returned positive COVID-19 tests since mandatory medical tests among staff at La Liga clubs began.
Real Sociedad goalkeeper Álex Remiro confirmed that he is one of the five players, who are all remaining at home as per La Liga guidelines.
The players will be tested again "in the coming days" and will only be allowed to return to training with their clubs after they give two consecutive negative results.
In and official statement, La Liga said that they would not be revealing the identities of the players but Remiro announced the news in a post on Twitter.
"Thank you very much for all the messages of encouragement," he wrote.
"I have tested negative for PCR and all I have are a few remains of antibodies that will soon pass and others will appear that will tell me that I am already cured.
"I will be back soon, now to keep hitting the bike."
La Liga began testing players and essential staff at clubs as part of the protocols in place for training to resume.
A number of clubs, including Barcelona, returned to training last week but with the players working individually.
It is hoped that elite level football in Spain will resume behind closed doors in June.
The full La Liga statement reads: "After carrying out the mandatory medical tests among essential staff at La Liga clubs in order to resume training, a number of positive COVID-19 cases have been detected.
"Concretely, five positive cases have been detected among players of La Liga Santander and La Liga SmartBank clubs, all of which are asymptomatic and in the latter stages of the virus.
"The identity of the players is unknown to La Liga in line with data protection legislation.
"The aggregate results have been sent by LaLiga to the CSD (Spanish High Sports Council) and to the Spanish Ministry of Health.
"Per La Liga protocol, The next steps for those who have returned positive COVID-19 results are:
1. Remaining in quarantine at home. Players will stick to the same individual physical training routine they have been following until now, in line with the club’s instructions.
2. They will be tested for COVID-19 again in the coming days and, after two consecutive negative results, will be able to rejoin training at the team facilities.
3. LaLiga will also offer tests to people living with those affected.
"LaLiga will continue to apply the Return to Training protocol approved by the CSD and Spanish Ministry of Health, in order to guarantee as much as possible the health and safety of all players, coaching staff and club employees."