The Polish Football Association (PZPN) said in a statement on Wednesday that Sousa, who visited Britain last week, "felt ill after returning to his home in Portugal and took a quick antigen test" for the virus and “the test came back positive.”
The statement added that a "PCR test performed" on Wednesday "confirmed the infection."
The PZPN also said "the standard isolation procedure was applied" for Sousa "in accordance with health and safety guidelines in force in Portugal.”
Earlier, PZPN spokesman Jakub Kwiatkowski said he hoped Sousa would only experience mild symptoms because he had been vaccinated against the coronavirus.
"If there are no complications, then there should be no problem with him taking part in the training camp ahead of our upcoming World Cup qualifiers against Andorra and Hungary," Kwiatkowski said in an interview with state news agency PAP.
The training camp starts on November 8, he added.
Poland is scheduled to play Andorra away from home on November 12 before taking on Hungary in their last World Cup qualifying fixture in Warsaw three days later.
(gs)
Source: PAP