Barcelona coach Xavi had six youngsters join senior training on Friday ahead of facing Celta Vigo.
He called up the players from Barça Atletic due to the club's long injury list.
Chadi Riad, Txus Alba, Román Vega, Barberà and Pelayo, in addition to Marc Casadó, who has been with the first team all week, took part in the session at the Ciutat Esportiva.
Barça are short on numbers after Andreas Christensen and Franck Kessie were added to the injury list this week.
Xavi was already without Hector Bellerin, Jules Kounde, Ronald Araujo, Frenkie de Jong and Memphis Depay for Tuesday's defeat to Inter Milan.
