Barcelona defender Pau Cubarsi is "fine" after requiring 10 stitches to close a cut on his face, manager Hansi Flick says.

The Spaniard, 17, was forced off in the 67th minute of Barcelona's 5-2 Champions League win against Red Star Belgrade on Wednesday after being caught by Uros Spajic's studs as he headed a corner clear.

Cubarsi, who made his debut for the club at the age of 16, needed medical attention on the pitch before his substitution after being left with a bloodied face and an open wound.

Flick said after the victory: "He needed stitches, but he's fine."

The club later posted a photo of a smiling Cubarsi with the caption: "I'm OK."