Real Madrid have concerns over the fitness of Gareth Bale, Casemiro, Mateo Kovacic and Karim Benzema ahead of Saturday's derbi at Atletico Madrid.
Although attackers Bale and Benzema are expected to be able to start, coach Zinedine Zidane has concerns in midfield.
It remains to be seen whether Croatia international Kovacic will recover from an ankle problem or Casemiro returns from the fractured shinbone that has sidelined him since early September, with Toni Kroos definitely out with a broken bone in his foot.
However, a fitness update on Real's official website said club captain Sergio Ramos and key midfielder Luka Modric were on schedule to start their first games in some time, having recovered from knee problems.
"Real Madrid players completed their second session of the week four days ahead of Saturday's game at the Vicente Calderon," the statement said.
"Karim Benzema, Casemiro and Pepe trained separately from their teammates, whilst Gareth Bale and Mateo Kovacic trained indoors. Sergio Ramos and Modric once again trained with the group."
A number of Madrid's other international players have yet to rejoin the squad, with Isco, Dani Carvajal and Nacho all having played in Spain's 2-2 friendly draw against England at Wembley on Tuesday.
After the game, right-back Dani Carvajal tweeted a video showing bruising to his foot after a clash with Danny Rose, but should be fine to play at the weekend.
Playmaker Marco Asensio suffered a bang to the ribs in Spain under-21s European Championship playoff first leg in Austria on Friday and was on the bench for Tuesday's return game.
He said: "I had a problem, but it is over now. I am fine," adding that Madrid had a strong enough squad to cover any absences on Saturday.
"There are other players available -- a derby is a derby," he said. "The players are there."
However, Madrid coach Zinedine Zidane will not want to take many risks with games at Barcelona in La Liga and Sporting Lisbon in the Champions League coming up shortly.