Barcelona finally register Lewandowski on eve of new season

However, French defender Jules Kounde remains unregistered with La Liga. Barcelona have spent 153 million euros on transfer fees alone to strengthen their squad, with Lewandowski the most notable new arrival from Bayern Munich.

That deal came a year after Barca were forced to let Lionel Messi go to PSG as the Catalan giants laboured under eye-watering reported debts of 1.35 billion euros. Faced with severe limits on spending in order to comply with La Liga's financial controls, Barcelona needed to raise money quickly to be able to invest in signings and, crucially, to register new players.

Earlier Friday, Barcelona sold another part of their media production unit "Barca Studios" for 100 million euros to Orpheus Media. Barcelona have already sold 25 percent of their domestic television rights for the next quarter of a century to US investment firm Sixth Street for some 400 million euros. They had already sold 24.5 percent of Barca Studios, which manages the club's digital business and audiovisual productions, to Socios.com for 100 million euros on August 1, and then another 25 percent to US investment firm GDA Luma for 100 million euros more.

In the space of a few weeks, 600 million euros had been brought in to fill the coffers. According to Marca, French international Kounde can only be registered if the club reduces its payroll. "So in the next few days, players in the squad will have to leave," claimed the daily.

Kounde signed at the end of July on a five-year deal. According to the Spanish press, Barca paid 50 million euros, with 10 million in bonuses, to recruit the defender from Sevilla.