Lionel Messi rejoined the rest of his Barcelona teammates at training on Wednesday.
Messi had been practising separately from the group since returning to the club on Monday.
He had not been with the squad since announcing he wanted to leave and then deciding to stay to avoid a legal dispute with Barcelona.
The Argentine superstar needed to pass two coronavirus tests before he could rejoin his teammates under incoming coach Ronald Koeman.
Also back with the group was Philippe Coutinho, who also had been practising separately.
Players who had been with their national teams for Nations League matches also returned, including Frenkie de Jong, Ansu Fati and Sergio Busquets.
Barcelona said defender Samuel Umtiti had been cleared by doctors after recovering from COVID-19.
Luis Suarez and Arturo Vidal, who like Umtiti are not in Koeman's plans for the season, also have been practising normally.
The club has scheduled a friendly against third-division club Nastic for Saturday.
Barcelona had their first two Spanish league games postponed because they played in the later stages of the Champions League.
The team's league debut will be against Villarreal at the Camp Nou at the end of the month.