Barcelona's Brazilian forward Neymar suffered a sprained right ankle which forced his substitution just 22 minutes into the Catalans' Copa del Rey, last 16 second-leg match at Getafe on Thursday.
"Neymar sprained the peroneal tendon in his right ankle. He will undergo additional tests tomorrow," said a statement on the club's official Twitter account.
The 21-year-old collapsed to the ground in pain after falling awkwardly as he tried to attempt a cross on the left side of the penalty box.
Alexis Sanchez replaced Neymar, but it was Lionel Messi, on his first start since returning from a hamstring injury, who opened the scoring just before half-time to put Barca 5-0 up on aggregate after their 4-0 win at the Camp Nou in the first-leg last week.