Joao Felix is set for a spell on the sidelines after Atletico Madrid confirmed he suffered a grade two sprain to a right ankle ligament against Valencia.
Portugal international Joao Felix, who joined Atletico in a €126million transfer from Benfica in the close season, limped out of Saturday's 1-1 LaLiga draw at the Wanda Metropolitano with 10 minutes remaining.
The 19-year-old appeared to twist his ankle in a challenge with Dani Parejo and left Diego Simeone's side down to 10 men, having used all three of their substitutions.
Atleti boss Simeone acknowledged in his post-match news conference that Joao Felix's injury "could be serious" and scans have confirmed a grade two sprain of the external lateral ligament.
"Joao Felix underwent an X-ray and MRI scan at the Clinica Universidad de Navarra on Saturday and the report indicates he suffered a grade two sprain of the external lateral ligament of the right ankle," Atleti stated on their website.
It remains to be seen how long the teenager will be out for, though reports suggest he will miss a minimum of two weeks.
Joao Felix could consequently be forced to sit out matches against Bayer Leverkusen, Athletic Bilbao, Deportivo Alaves and Sevilla.
Since his club-record move to Atleti, the forward has scored two goals and providing one assist in LaLiga.