Lazio coach Stefano Pioli says they need to find a new striker signing this week.
Filip Djordjevic fractured an ankle in the win over AC Milan.
Pioli said: "I feel very sorry for Filip, he's a great guy and a top player, I'm sure he'll come back even stronger than before.
"We're evaluating the situation, but we definitely have to act.
"We're looking for someone with the same characteristics as Djordjevic, we're looking for someone who has the right ones for us.?
"We don't have much time, as it was something unexpected but the club has shown they're ready to act.
"[Brayan] Perea [on loan at Perugia], would have the advantage of knowing the club, and has characteristics which suit our attacking game.
"But we're looking at other alternatives, along with the club."
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