Barcelona’s hopes of signing a successor to their departing goalkeeper Victor Valdés and the teenager dubbed “the new Lionel Messi”, Alen Halilovic, have been hit after they had a year-long transfer ban imposed on them on for breaching Fifa’s rules on the transfer of players aged under 18.

The 14-month transfer ban raises serious questions about the club’s immediate future, with Fifa applying the sanction against Barca for signing 10 minor players and committing “several other concurrent infringements”. They have been fined £305,000 and if the punishment stands they will not be able to sign players until the summer of 2015.

Barca are expected to appeal against Fifa’s decision via the court of arbitration for sport, but the news comes as a major blow for the Catalan club and the latest in a string of recent embarrassments for the board.

It casts doubt over moves already agreed for the £10m Borussia Mönchengladbach goalkeeper Marc-André ter Stegen and the Croatian 17-year-old Halilovic, who turns 18 in June. Stegen was seen as the successor to Valdés, who is out for seven months with a knee injury and has said he is leaving the club in the summer.

The Spanish champions have a number of promising South Korean youngsters on the books, including the highly-rated Lee Seung Woo, plus many other under 18s from Cameroon. The players in question were registered and participated in competitions with the club between 2009 and 2013, while the Spanish Football Federation (RFEF) has also been sanctioned by Fifa for the same breaches.

Fifa said in a statement: “FC Barcelona has been found to be in breach of article 19 of the regulations in the case of 10 minor players and to have committed several other concurrent infringements in the context of other players.

“The disciplinary committee regarded the infringements as serious and decided to sanction the club with a transfer ban at both national and international level for two complete and consecutive transfer periods, together with a fine of 450,000 Swiss francs.