The former Spain international was presented in the club’s Anoeta stadium a fortnight ago having completed his move from Manchester City as a free agent earlier this month.
However, later that day – and before he had met his teammates – Silva tested positive for Covid-19 and had to enter a two-week period of quarantine to recover, which has now expired.
Marca outline how he was in training for the Basque club today and he is likely to be available to debut against Real Madrid this weekend.
The 34-year-old had amassed 434 appearances for City, scoring 77 goals, providing 137 assists and winning four Premier League titles after joining from Valencia in 2010, but was out of contract this summer.
The playmaker has retired from international duty but won a notable 125 caps for La Roja, scoring 25 goals and winning three major tournaments – winning two European Championship crowns alongside the 2010 World Cup.