Barcelona to keep big money stars on the sidelines for six months

More big money deals could follow. A FIFA ban on making official signings until January 2016 has not stopped the Spanish giants from plunging into the market ahead of a messy year of internal tensions and high profile trials for Barcelona and some of its stars.

Barcelona on Monday announced they had beaten Chelsea to secure 28-year-old midfielder Turan from Atletico Madrid on a five-year deal for a fee that could reach 41 million euros.

That follows the 18-million-euro signing of right-back Vidal from Sevilla last month.

Others are expected to follow with media reports indicating Barcelona are trying to line up a deal for Juventus' midfielder Paul Pogba which would see him arrive at the end of next season.

Barcelona were banned from making new signings in 2015 after FIFA found them guilty of breaching rules on the transfers of players aged under 18.

Turan, captain of Turkey's national team and a prolific goalscorer with Atletico, has not yet indicated what he thinks about sitting out half a season.

Vidal says it is a sacrifice worth making to join Europe's most successful team of the past decade.

"When I was told that it would really happen, I didn't think it was a hassle to come and spend a few months without playing," he said just after the transfer was announced.

Turan and Vidal have arrived at a complicated time for Barcelona as the team prepares for the election of a new president on July 18.

Transfer policy has been at the centre of the debate between incumbent Josep Maria Bartomeu and challenger Joan Laporta.

Because of the election, the Barcelona managing committee could not approve the Turan transfer and a clause in the deal was included saying that he could be sold back at a 10-percent discount if the new president so decides.

Laporta called the Turan deal "improper" and said Bartomeu should have completed the transfer before resigning to stand in the campaign.

"The urgency of this operation is out of order. The only explanation is that it favours Bartomeu's candidacy.

"There was already a lack of transparency in Neymar's signing and I think that it is insane that the management committee is playing this game," he said.

Barcelona and their top manager are to stand trial over the transfer of Neymar. Spanish prosecutors allege that secret commissions were paid as part of the deal.

The club bought the Brazilian captain in 2013 for what they said was 57 million euros ($41 million). A Madrid judge says the fee was closer to 83 million euros.

Fellow striker Lionel Messi could also stand trial on tax fraud charges. Investigators allege his father Jorge organised a complex network of companies that kept 4.1 million ($5.5 million) from tax authorities between 2007 and 2009.