Barcelona prepared for Wednesday's Copa del Rey clash at third-tier Linares undeterred by the Covid-19 positive result of new signing Ferran Torres.
The news would have given more headaches to manager Xavi, who had unsuccessfully asked for Sunday's match against Mallorca to be postponed.
The Catalans beat Mallorca 1-0 in a match where they were missing 14 players, eight of them due to Covid-19: Sergino Dest, Philippe Coutinho, Ez Abde, Jordi Alba, Alex Balde, Ousmane Dembele, Gavi and Dani Alves.
Samuel Umtiti and Clement Lenglet also tested positive during the week but were cleared after returning negative tests on Sunday.
Torres, 21, had moved to Camp Nou on a five-and-a-half-year contract from Manchester City for an initial fee understood to be £46.7 million ($62.8m), with add-ons.
Meanwhile, Xavi said he is hopeful Ousmane Dembele will decide to stay at Barcelona. Dembele's contract expires in the summer and a new deal is yet to be agreed, with Barca's negotiating power hampered by mounting debts.
Renewing the 24-year-old's contract on reduced terms would also allow Barcelona to register new signing Torres, who currently can't play due to La Liga's spending limits.
"I am hoping that he makes an effort," said Xavi. "This sporting project is the best one for him. He will not be as happy anywhere else as he is at Barca. We are going to see what he decides. I am calm and waiting for news. It does not depend on me. It depends on the club, the player and the agents."