FC Barcelona are yet to register Lewandowski and other new signings ahead of La Liga opener

FC Barcelona are yet to register their summer signings ahead of this weekend's La Liga opener with Rayo Vallecano.

Barcelona's ongoing financial crisis is not hidden anymore and the La Liga giants need to meet the Spanish top-flight's strict financial regulations.

The Catalan club signed Robert Lewandowski from Bayern Munich, Brazilian striker Raphinha from Leeds, French centre-back Jules Kounde from Sevilla, defender Andreas Christensen from Chelsea, and midfielder Franck Kessie from AC Milan.

Barcelona are still to satisfy La Liga and are now working on activating what is being referred to as a fourth 'financial lever', a significant stake in their Barca Studios commercial arm, in order to comply, according to a report in BBC Sport.

In addition, senior centre-back Gerard Pique has taken a pay cut. La Liga believes these changes will allow Barcelona to start registering new players, although there it is understood that this may be done on an individual basis rather than all at once.

Barcelona's financial crisis is one of the reasons for midfielder Frenkie de Jong's uncertain future. While he is contracted with Barcelona until 2026, the club has put the Dutchman on the transfer list this summer. However, Barcelona owe de Jong millions in deferred payments from a restructuring of his Barcelona contract, which has come into force this season.

De Jong has made it clear that unless Barcelona clear the dues, he will not leave, despite massive interest from Premier League giants Manchester United and Chelsea.

Meanwhile, in a recent interview, Barcelona president Joan Laporta insisted that the club wants the former Ajax midfielder to stay at Cam Nou.

"Frenkie de Jong is a Barcelona player of great quality and we want him to stay. With him and his teammates, we have a very powerful midfield. He has offers, but we want him to stay and he wants to stay too," Laporte told TV3.

Barcelona are also trying to sell on a number of players, including defender Samuel Umtiti and forward Martin Braithwaite, who was booed before Sunday's pre-season game against Pumas at the Nou Camp.

"They have understood that the best thing is to go play for another team. Their contracts have always been respected, but the time has come when they have to take a step forward. This week they have to fix both of them," added Laporte in the same interview.

Barcelona did not win any trophy last season. Xavi's arrival improved the situation though as Barca finished second in the La Liga table despite struggling at No. 8 or 9 for the majority of the campaign.