Hansi Flick has said he has no control over Dani Olmo's registration problems as Barcelona face the prospect of not having their new signing available to face Rayo Vallecano on Tuesday.

Olmo, a 55 million ($61m) arrival from RB Leipzig, has missed the first two matches of Barça's season because his inscription has not been processed with LaLiga due to the club's continued financial woes.

Barça are in excess of their league-imposed spending limit and, while they are working on various outgoings and deals in the hope of registering Olmo to face Rayo, sources have told ESPN he is unlikely to feature once again.

"I always hope, but it's like it is," Flick told a news conference Monday when asked about the Olmo situation.

"It will be great to have him in the team against Rayo, but we will see what happens. This is a thing the player or the coach cannot control.

"We both know, we spoke also about the situation, we know it's a little bit difficult here in Barcelona.

"I believe in the club and I think we can put him on a list [soon] and hopefully it's for the match tomorrow."

As Barça are in excess of their spending limit -- a cap which all Spanish clubs have and is roughly determined by the difference between a team's revenue minus non-sporting outgoings and debt repayments -- they must reduce the wage bill and/or increase revenue to register new additions.

A series of exits this week will ease the issue, with Vitor Roque, Clément Lenglet, Mika Faye and Álex Valle all leaving the club, but sources suggest that still won't be enough to register Olmo.

Flick admitted it is far from ideal for the Spain international, who returned to Barça -- where he came through the academy -- after a fine performance at the European Championship this summer.

"Of course every player who cannot play for this reason is not happy," Flick said. "Of course he knows this, but if he's on the list I'm 100% sure that he's ready to play."

Despite their financial problems, Barça have made an impressive start to the campaign under their new German coach, beating Valencia and Athletic Club in their opening two games.

It has served to lift the mood around the club following a difficult summer in the transfer window, with many tipping Real Madrid to run away with LaLiga following the addition of Kylian Mbappé.

"The focus is always to win the championship," Flick said of his team's aims. "It's a long, long race to win this but we started well.

"It could change next week, in the next situation it can change totally. We're happy with how we started, it gives us the confidence, the belief in each other.

"We're not looking in the past, though, we're looking at the next match, at Rayo, and that's very difficult for us."

Barça have no new injuries ahead of the trip to Vallecano but remain without Ronald Araújo, Andreas Christensen, Frenkie de Jong, Gavi and Ansu Fati.