Barcelona welcomed Robert Lewandowski, Frenkie de Jong, Pedri and Jules Koundé back to training on Friday but coach Xavi Hernández remained coy over their availability for Saturday's Clásico (10 a.m. ET, stream live on ESPN+).
Raphinha also returned to training this week, with Sergi Roberto the only player definitely ruled out of Real Madrid's visit to the Olympic Stadium this weekend in LaLiga.
- Stream on ESPN+: LaLiga, Bundesliga, more (U.S.)
- Ultimate Clásico preview: Predictions, Key players & form guide
Lewandowski, De Jong and Raphinha had all been rated as touch-and-go to feature against Madrid, but Xavi said last weekend Koundé would not be fit, while Pedri's chances of taking part had decreased throughout the week.
"I was surprised [that they were all able to train]," Xavi said in his prematch news conference on Friday.
"The sensations during the session were very good. We will see how they feel later and will name the squad on Saturday. It's fantastic to have them all back training.
"Players we had ruled out want to play. Everyone is making a huge effort because they want to be involved in the Clásico, but we won't start anyone who is not 100%."
Pedri has not featured since August due to a thigh injury, with the length of his recovery raising doubts about his fitness following a string of similar injuries over the last 18 months.
"There is no problem with Pedri," Xavi added. "We had deadlines in place and he's more or less ticked them all off during his rehabilitation."
Lewandowski, De Jong, Raphinha and Kounde have not been out for as long. If they are not ready to face Madrid, they will come into contention for the trip to Real Sociedad next weekend.
Madrid lead LaLiga ahead of the weekend's games, level on 25 points with Girona, but Barça, the league's only unbeaten side, are just a point back and can overtake Los Blancos in the table with a win.
"This game means a lot," Xavi added. "It's the Clásico and every player in the world wants to play in it. We are in good form, in terms of performances and results.
- If soccer had recruiting classes, where would Clasico rivals rank?
"We have won two games at home this week and it will be a massive morale and confidence boost to win. It's also vital in terms of our objective in the league this season, which is to win it."
The spoils were shared between the two teams last season. Barça beat Madrid in the Spanish Super Cup final and at Spotify Camp Nou en route to the LaLiga title, while Madrid won at the Bernabeu in the league.
In the Copa del Rey semifinal, Barça edged the first leg 1-0, but Madrid won the second leg 4-0 to advance to the final, where they beat Osasuna.
"It's 50-50," Xavi said ahead of the 255th official meeting between the sides. "There is no clear favourite for the game. There hardly ever is in the Clásico. It is unpredictable.
"It's one of the biggest rivalries in the game. I don't know if the biggest -- in Argentina there is Boca Juniors-River Plate and we have the Seville derby and the Basque derby here in Spain -- but in terms of domestic club football, it's the biggest game there is."