Jules Kounde is the only one of Barcelona's new signings who was not registered on the eve of the LaLiga season.
Barca head coach Xavi on Friday revealed the club were "very optimistic" that their new recruits would be registered, but all five may not be given the green light for their first match of the LaLiga campaign against Rayo Vallecano on Saturday.
It later emerged that Robert Lewandowski, Raphinha, Andreas Christensen and Franck Kessie have been registered along with Ousmane Dembele and Sergi Roberto, who signed new contracts
Centre-back Kounde's registration has not been sanctioned by LaLiga despite Barca having activated a fourth economic lever on Friday.
It had been reported that Kounde may be the last of the five new recruits the Catalan giants have brought in to be registered, given the big-money signing from Sevilla underwent surgery to repair a minor pelvis injury in June.
Barca have been busy raising funds to try and meet LaLiga's salary limits and sold a further 24.5 per cent of their production company for €100million, having also agreed a hugely lucrative sponsorship deal with Spotify and sold a percentage of broadcast rights.
The Blaugrana have lowered their wage bill by offloading players and could also sell Frenkie de Jong and Pierre-Emerick Aubameyang, who have both been linked with Chelsea.
Blaugrana head coach Xavi said in a press conference on Friday he was prepared for the possibility that some of his new men may not be eligible to play this weekend.
He told reporters: "We are working hard and everyone at the club is very positive. Maybe not 100 per cent [of the players will be registered], but we are optimistic. We'll see. The club has signed very well, I am very excited about the players we have signed. We have time until tomorrow and now we are very optimistic."
Barca are expected to make Chelsea full-back Marcos Alonso their next signing and they continue to be linked with Manchester City midfielder Bernardo Silva.