Barcelona's new goalkeeper Wojciech Szczesny will not make his debut against Alaves on Sunday and will instead have to wait until after the international break.

The club signed the Pole as a free agent on Wednesday, with the goalkeeper reversing his decision to retire so he could come to the team's aid following Marc-Andre ter Stegen's season-ending injury.

Ter Stegen suffered a serious knee injury against Villarreal last month, and Inaki Pena has featured in the last three games for Barcelona, most recently keeping a clean sheet in their 5-0 win over Young Boys in the Champions League.

And it looks like Pena is set to start between the sticks against Alaves, too, with Hansi Flick confirming that Szczesny is not yet available for selection. 

"Szczesny is in good shape and, with his experience, character and quality, I think he is the very best option for the club," Flick told reporters.

"It's very good to have him, he will help us a lot, but he is not with us against Alaves.

"I am sure after the international break Szczesny will be an option for us. For him also, to play for Barca will be great. We will see how he is doing in training. We have a lot of time."

The Catalan side have a tough run after the international break, hosting Bayern Munich in the Champions League three days before visiting Real Madrid in LaLiga on October 26.

They are in a strong position though, sitting top of the table heading into their match against Alaves, though did suffer their first loss of the domestic season against Osasuna last weekend in a 4-2 defeat.

With 25 goals to their name already, they have made their best scoring start to a single campaign since 2016-17 (26).

However, Flick admitted his decision to rest key starters had an impact in that loss, and accepted the players would not like his choices.

"It's normal to get angry, everyone wants to play more. Those changes had to be made. It's a decision that they have to accept, and they did," he added.

"Lamine Yamal [a 59th-minute substitute against Osasuna] complained that he wasn't receiving many balls, but now he can work on fixing that.

"We have to avoid the many mistakes we made at Osasuna. We need to have more control and possession. It is going to be a high-intensity game at Alaves." 

Barcelona have signed Wojciech Szczesny as a free agent, with the goalkeeper reversing his decision to retire after the Blaugrana lost Marc-Andre ter Stegen to a long-term injury.

Germany international Ter Stegen underwent surgery after suffering a rupture of the patella tendon in his right knee last weekend and is expected to miss the rest of the season.

Inaki Pena was initially expected to cover for Ter Stegen, but Barca have now reinforced their squad with the signing of former Arsenal man Szczesny.

Szczesny had announced his retirement from football last month after terminating his contract with Juventus, where he had been a regular after replacing Italy great Gianluigi Buffon between the sticks.

Szczesny won Serie A and the Coppa Italia three times each with Juve, making more than 250 appearances for the club, but he then lost his place to close-season recruit Michele Di Gregorio.

Barcelona are top of LaLiga with 21 points from eight games and Hansi Flick's side next visit Alaves on Sunday, looking to bounce back from last week's defeat at Osasuna. 

Barcelona will be without injured goalkeeper Marc-Andre ter Stegen for several months, but Hansi Flick is confident they have a capable deputy in Inaki Pena.

Germany international Ter Stegen underwent a successful operation on Monday after suffering a complete rupture of the patella tendon in his right knee.

The 32-year-old suffered the injury in Barca's 5-1 win at Villarreal in LaLiga on Sunday and is expected to be out for at least eight months, according to Spanish media reports.

Despite Ter Stegen's season likely being over, Flick is remaining upbeat, backing academy product Pena to handle the step up.

"Inaki is doing very well, in pre-season too. He has worked very hard to be here. He is focused and ready to play," Flick said ahead of Wednesday's home game versus Getafe.

"We are confident but we also have to look at what we do because the players at the back are very young. For the moment, we don't feel under pressure and we trust in Inaki."

Having joined Barcelona's La Masia academy aged 13, 25-year-old Pena has made 23 first-team appearances, conceding 39 goals and keeping five clean sheets.

Pena made 10 league appearances for Barca last term, with his save percentage of 56.4% falling some way short of Ter Stegen's 73.5%.

Pena also conceded 17 goals from 13.89 expected goals on target (xGoT) faced, giving him an underperformance of 3.1 in terms of goals prevented. Ter Stegen, by contrast, conceded 27 times from 27.84 xGoT faced.

The Catalans were already without new signing Dani Olmo and fellow midfielders Gavi, Frenkie de Jong, Marc Bernal and Fermin Lopez, plus defenders Ronald Araujo and Andreas Christensen, due to injuries.

However, they have made a perfect start to the season under Flick, with six straight wins putting them top of LaLiga, four points ahead of reigning champions Real Madrid in second.

But the former Bayern Munich boss is striving for more, adding: "We analysed the game against Villarreal and we saw a lot of things that can be improved. 

"We haven't reached the end of the road. You can always do more. We are moving forward step by step."

Xavi believes he is on the way to creating a “great Barcelona” side but he wants improvement as they close their Champions League group stage at Royal Antwerp.

Barca are already guaranteed a place in the last 16 and are virtually assured top spot in Group H, barring some unlikely results.

The Spanish club have not been at the top table of European football for a while, having last won the Champions League in 2015, but Xavi, who was a key player in the side that dominated the game a decade ago, can see progress.

“We want to end the group stage having done what we need to do,” he said on Barcelona’s website.

“We have to be much more effective. We create a lot of chances to win games earlier. We have to be better in front of goal, but also improve our defensive robustness.

“We have to show consistency to achieve targets and trophies. We are on the way to creating a great Barca side.

“The team is together and a close-knit group.”

The Belgian side have lost all five of their group games so far, but Xavi still respects the team managed by his former team-mate Mark van Bommel.

View this post on Instagram

A post shared by FC Barcelona (@fcbarcelona)

“They are a good team and Van Bommel is doing a very good job, and he wants to leave a mark playing football based on teamwork,” Xavi added.

“We will decide which players will feature after training and prior to the game, but it is a good chance to give opportunities to young players and others who haven’t played that much.

“Logically we will make changes.”

Inaki Pena is almost certain to continue in goal after Marc-Andre ter Stegen had back surgery last week.

“The injury to Ter Stegen is not good news,” the goalkeeper said. “It makes me proud to be playing in this shirt.

“I have trained every day thinking that this day would come because you never know what can happen. At a club like Barca you can’t relax for a single day.

“I have been training for a long time with Ter Stegen and it is a pleasure to be able to learn from one of the best players in the world.

“Picking things up from him has made me a better goalkeeper.”