Arsenal manager Mikel Arteta is well aware of the quality of former Tottenham star Adel Taarabt.
Benfica are one of the underdog teams in the competition, and the Gunners know they must be at their best to progress to the last 16.
The game is finely poised after Arsenal got a 1-1 draw away from home.
Asked if he remembers playing against Taarabt, Arteta told reporters: "Yes, he used to play as a No 10 and he was a super talented and very creative player.
"He had a really good season in the Premier League and it was very hard to play against him, because I played very close to him a few times.
"He was a player with an enormous talent. He's changed his position a little bit and a bit with his discipline too.
"It's nice to see him back playing."