Real Madrid trained without injured left-back Marcelo on Monday ahead of their midweek La Liga game at Leganes.
The Brazil international sustained a muscular problem during Sunday's 5-3 win at Real Betis while making his 19th league start for Real and was replaced in the 30th minute.
Marcelo is expected to undergo tests on Tuesday.
Madrid coach Zinedine Zidane said after the game he hopes the 29-year-old will not face a lengthy absence, with Real playing at Paris Saint-Germain in the return leg of their Champions League round of 16 tie on March 6.
Marcelo has started in 29 games for Real this season and has scored three goals, including Real's third in last week's 3-1 win over PSG in the opening leg.
Madrid midfielder Toni Kroos is still sidelined with a knee ligament injury while defender Jesus Vallejo trained separately on Monday as he continues his recovery from a right hamstring problem.
Fourth in La Liga and 17 points adrift of leaders Barcelona but with a game in hand, Real play at Leganes on Wednesday before hosting Alaves this weekend.