Barcelona will have to wait a little longer to count on Ousmane Dembele, while Atletico Madrid could be without Alvaro Morata when they face Liverpool.
The France forward left team practice on Monday complaining of muscle pain in his right leg. The club said the problem was prompted by muscle fatigue.
Dembele was in the final stages of his recovery from a hamstring injury that has kept him sidelined since November. He had just recently rejoined his teammates in full practices.
The team did not say when he is expected to be back in action.
The club did not make any major signings in the winter window to immediately boost their attack.
Elsewhere in La Liga, Atletico Madrid's Morata could miss the Champions League game against Liverpool because of a right leg muscle injury.
Scans revealed the injury on Monday, two days after Morata was hurt in the 1-0 loss at Real Madrid and had to be substituted in the second half.
Atletico did not say exactly how long Morata is expected to be sidelined. They host Liverpool on Feb. 18 in the first leg of the competition's round of 16. The second leg will be on March 3 in England.
Atletico coach Diego Simeone also can't count on forwards Diego Costa and Joao Felix because of injuries.
Barcelona are second in La Liga, three points behind Real Madrid ahead of a Sunday match against Real Betis.
Atletico are in sixth place after the loss to Real, 13 points off the lead after 22 matches. They face Granada at the Wanda Metropolitano on Saturday.
Information from Reuters and the Associated Press was used in this story.