Atletico Madrid have confirmed that Mario Mandzukic will undergo surgery on a broken nose tomorrow, but it is unknown whether the striker will miss any games.
The 28-year-old suffered the injury during Atletico's 3-2 defeat to Olympiacos in their Champions League group match last night.
A statement on Atletico's official website read: "Tests on Wednesday show Croatian Mario Mandzukic suffered a broken nose. He will undergo surgery on Thursday 18, at 9pm in the FREMAP Majadahonda clinic."
Mandzukic, who got on the scoresheet in last night's match, joined the Spanish club from Bayern Munich on a four-year deal in the summer.