Barcelona coach Luis Enrique has said Arda Turan and Aleix Vidal will make their debuts in Wednesday's Copa del Rey last 16 first leg at home to Espanyol.
Turkey playmaker Turan and Spain international Vidal cost over €50 million between them when they were signed from Atletico Madrid and Sevilla in the summer.
But they were only eligible to be registered on Monday after the club's FIFA-imposed transfer ban expired
Both have been included in the 16-man squad for a second meeting with Espanyol in four days, with Lionel Messi, Neymar, Luis Suarez and Andres Iniesta also called up.
Luis Enrique told a news conference both Arda and Vidal were ready to go straight into the action, adding that their versatility would offer him new options.
"Arda and Aleix Vidal are well, they are happy and they will both take part," Luis Enrique said. "We will see how it goes, but both are ready to play 90 minutes.
"Arda has played with his national team, and Aleix is very good physically. Arda can play as an attacking midfielder or out wide. Aleix can play in three positions -- full-back, interior or out wide. They can bring us many things."
Espanyol battled their way to a 0-0 draw in Saturday's La Liga derbi at the RCDE stadium, with some observers claiming they had adopted an over-aggressive approach.
But Luis Enrique said: "I expect a different game this time. I did not want to talk too much about it just afterwards, and I won't do so now.
"We played a very good game there and made seven very clear chances, although there are still things we can improve upon. All our players are ready for this game."
Claudio Bravo is the only first team regular rested for Wednesday's fixture, with right-back Douglas, young attacker Sandro Ramirez and experienced utility man Adriano Correia all left out amid rumours at least one could leave this month.
With the ban over, Barca registered a total of 77 players across all age groups, with Korean teenager Seungwoo Lee among the younger players who could break through into the senior setup.
"It is very important that Lee, just like the other players who were penalised, has a chance to play again," Luis Enrique said.
The former Real Madrid player was asked for his views on Zinedine Zidane replacing Rafa Benitez as the club's first team coach.
"Benitez's sacking was not a surprise -- this often happens in modern football," he said. "Any coach at any time in their career can be sacked.
"The chain always breaks at the weakest link, which is the coach. This career is risky, like bungee jumping, it's the first thing you learn about it."
He said it was too early to say whether Zidane would be a good choice and added: "I don't know him as a coach, and cannot make a judgement or comment.
"Those of us who have been former players have an advantage when it comes to coaching, but you are judged for what you do as a coach. Some great coaches were never players -- it does not guarantee you success."
Barcelona squad: Marc-Andre ter Stegen, Jordi Masip, Gerard Pique, Ivan Rakitic, Sergio Busquets, Dani Alves, Arda Turan, Andres Iniesta, Luis Suarez, Lionel Messi, Neymar, Javier Mascherano, Marc Bartra, Munir El Haddadi, Jordi Alba, Aleix Vidal, Thomas Vermaelen, Jeremy Mathieu.