Tottenham manager Mauricio Pochettino warned his players to be "careful" against Gonzalo Higuain as the Juventus striker, who he sees as one of the game's best along with Harry Kane, prepares for a timely return from injury.
Higuain has been sidelined for Juve's last two matches with an ankle problem.
But the 30-year-old, who scored twice and missed a penalty in the 2-2 first-leg draw in Turin last month, now looms as a major threat to Spurs' hopes of reaching the quarter-finals, with Pochettino in no doubt over his quality.
"I think he is one of the greatest strikers in the world, with Harry Kane," Pochettino said of his compatriot.
"We know his talent very well and sometimes it is not easy to stop him. Like Paulo Dybala or Lionel Messi, this type of player.
"We need to be careful with him but also careful with all of their players we are going to play against on Wednesday."
Spurs are in a strong position after Kane and Christian Eriksen both struck valuable away goals in the first leg, but Pochettino insists his side will not sit back and hold on for a low-scoring draw on the night.
"We are a brave team - very positive people that love the challenge," he said.
"We need to think we can win, we always think in this way, and then what happens will be a consequence of our performance.
"If we perform the way we usually do we will be close to winning and going through to the next stage."