Sanchez appears to have settled down quickly in North London following his move from Barcelona in the summer, and Zabaleta is fully prepared for the threat posed by the Chilean forward.
"Sanchez is a very quick, sharp player who can play wide or as a striker, but I feel he is most dangerous when he is on the flanks," the Argentina full-back told reporters.
"He did very well at Barcelona and he is a difficult player to face because you know you are in for a tough afternoon when you face him.
"He is also works very hard for the team, especially when they don't have the ball and he has become a very important player for Chile so he is a great signing for Arsenal."
Zabaleta is expecting to be fully fit for the game against the Gunners despite picking up on a knock while on international duty.