Arsenal defender Vermaelen: Ibrahimovic is complete striker
Vermaelen is expected to go head-to-head with Barca centre-forward Zlatan Ibrahimovic.
"You are aware of the qualities of the opponents, but you also know what your own strengths are," he told arsenal.com.
"Zlatan is a complete striker. He is a tall, strong player and has developed a lot. I know his qualities, but I will play my own game. Lionel Messi is a very good player, one of the best players in the world with a lot of qualities.
"He is a real footballer who people enjoy watching play. However, there will be no time to be intimidated tomorrow.
"You have to be focused on your own performance and the team's performance. You cannot look at how Messi is, because you have to play your own game."