The scoreline is locked at 1-1.
"We've got a tough match ahead of us tomorrow. We must play our own game," Lamela said.
"It's very important and we have to win.
"I think of Fiorentina as a strong team that will try and impose their typical style.
"It's going to be an open game as both teams want to dominate. I hope it's going to be a fun match."