The club had started disciplinary action on Tuesday and stripped Ter Stegen of the club captaincy on Thursday over a row concerning his fitness after he underwent back surgery at the end of July.

Local media reported that the 33-year-old had refused to cooperate and release his medical details so the club tried to have him classified by La Liga as a long-term injury, which would allow Barcelona to deduct part of his pay from their official wage bill.

But in a late night statement Barcelona reported the player had signed the necessary paperwork.

"The disciplinary file is considered closed and the player regains the first team captaincy with immediate effect" Barca added.

Earlier Friday Ter Stegen had taken to social media to defend himself.

"In recent weeks, many things have been said about me - some of them entirely unfounded," he wrote on Instagram. "Therefore, I feel it is necessary to express my version of events respectfully, yet clearly."

"I am fully willing to collaborate with the club's management to resolve this matter and to provide the requested authorisation," Ter Stegen wrote.

With the new Liga season approaching, Barcelona are again struggling to satisfy Spanish financial fair play rules. If they cannot, they may not be able to register new players.

Ter Stegen said if the club was in a financial bind, it should not blame his back problems.

"I would also like to clarify that all of the club's signings and contract renewals were completed prior to my surgery," he wrote.

"The decision to undergo surgery was fully approved by the club, and always with the intention of prioritising my health and long-term sporting career which of course are fully aligned with those of FCB to have myself available on the pitch as soon as possible to keep winning trophies."

He added that his new surgery should not interfere with the "registration of other colleagues whom I greatly respect and look forward to share locker room with for many seasons".

"My commitment to these colors remains absolute."

Ter Stegen's place is under threat from one of the summer signings, 24-year-old Joan Garcia, and 35-year-old Wojciech Szczesny, the Polish veteran who has been rewarded with a contract extension for taking over during last season's Liga title-winning campaign.