Real Madrid talisman Cristiano Ronaldo departed the action deep into stoppage time of Wednesday's win over Villarreal clutching his right hamstring.
The sight will come as a concern for Madrid, who cruised to a 3-0 victory at the Santiago Bernabeu to keep pace with Barcelona and Atletico Madrid in a thrilling La Liga title race.
After holding the back of his right leg, Ronaldo walked from the field and sat on the bench, with Madrid having used all three substitutes.
Any injury to the Portuguese superstar would come as a major blow to Zinedine Zidane's side, who are a point behind Barca and Atletico with four games to go and have a Champions League semi-final to come against Manchester City.
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.