Thomas Vermaelen, Douglas and Munir El Haddadi will return to Barcelona training on Wednesday, but sources have told ESPN FC that Barca are prepared to let all three leave.
New coach Ernesto Valverde is looking to remodel his squad, but there has been no significant interest in any of the trio of players so far.
Vermaelen returns after spending last season on loan at Roma, where he was plagued by injury problems.
Douglas and Munir are back from loan spells with Sporting Gijon and Valencia respectively.
Sergi Samper and Gerard Deulofeu will also be present, having returned from Granada and Everton respectively -- the latter cutting short his break to come back early after taking part in the European Under-21 Championship with Spain this summer.
The majority of Barca's players are due to begin their preseason schedules on Wednesday, with B team players Adrian Ortola, Marlon Santos, Carles Alena, Marc Cucurella and Sergi Palencia all called up by Valverde.
Denis Suarez, who also took part in the U21 Championship, is one of six players due back at the Ciutat Esportiva on Friday.
Arda Turan, Lionel Messi, Neymar and Gerard Pique will then join their teammates on Saturday due to commitments with club sponsor Rakuten in Japan.
But Barca have not yet confirmed when Andre Gomes and Marc-Andre ter Stegen will be back.
Both were given extended time off following their involvement in the Confederations Cup with Portugal and Germany respectively.
Valverde and his players fly to New York next week ahead of International Champions Cup fixtures against Juventus, Manchester United and Real Madrid.