Barcelona have ruled goalkeeper Neto out for up to eight weeks with a fractured left wrist.
The new signing underwent an operation on Tuesday after suffering the injury during training prior to the 4-0 weekend win over Napoli in Michigan.
The 30-year-old joined Barca from Valencia in June in a deal worth an initial €26 million (£23m/$30m) as Jasper Cillessen moved in the opposite direction.
His absence leaves the La Liga champions without an experienced competitor for first-choice Marc-Andre ter Stegen ahead of Friday’s season opener against Athletic Bilbao.
Inaki Pena, 20, is expected to be promoted from Barcelona B after travelling with Ernesto Valverde’s squad to the United States.
The timescale placed on Neto’s recovery could keep him out until after the international break in October.
Neto is a verteran of 67 top flight games in Spain, while the well-travelled shot-stopper has also featured in Italy’s Serie A for Juventus and Fiorentina, and Brazil’s Serie A with Athletico Paranaense.
Despite having played for such storied clubs, he is looking forward to getting going with Barca and is hopeful the silverware will follow.
“It’s a dream for any footballer. When you talk about Barcelona, ever player at the highest level wishes to play for a team like this one,” Neto told SPORT.
“It’s very different. It means your hard work has paid off when your club can compete for every trophy available.
“For me, as someone who likes to always win, to compete at the highest level is the best.”
Barca are also set to be without key man Lionel Messi for their opening league outing as the Argentine superstar is nursing a calf problem.
“He’s in the recovery process and I don’t know if he will be ready for the start of La Liga,” Valverde told a news conference after a 4-0 win over Napoli in Michigan on Saturday. “It’s looking difficult.”
That success was Barcelona’s fourth on the spin in pre-season and marked the first goal in the famous Blaugrana for summer arrival Antoine Griezmann, the club’s marquee signing from Atletico Madrid.