Having reached the Spain national team shortly after making his professional club debut, he appeared in two World Cups and as many European Championships.

[2] He had not yet appeared in La Liga when he was summoned by first-team manager Johan Cruyff to a UEFA Champions League group stage game away against Galatasaray S.K.

[4][5] After being deemed surplus to requirements by coach Louis van Gaal, Sergi joined Atlético Madrid,[6] where he still posted three respectable seasons although he collected a total of 33 yellow cards.

Shortly after having been promoted into Barcelona's main squad, Sergi made his debut for Spain on 9 February 1994, in a friendly with Poland in Santa Cruz de Tenerife in which he scored his only international goal.

[8] In July 2009, after several years working in marketing and running football camps for youngsters, Barjuán returned to Barcelona, being named its Juvenil B manager.

[21] In June 2021, Barjuán was appointed at FC Barcelona Atlètic on a two-year deal, replacing Francisco Javier García Pimienta.