Cahill made his debut in the friendly defeat to Tottenham this week.
"You saw a little cameo of what he can do. He's clever,'' Arsenal legend Henry told the New York Post. "You saw Teemu (Tainio) and Tim not running a lot, just putting yourself playing where you should be. Football is not only running, going up-and down without playing the ball.
"They were putting themselves in the pockets where they knew maybe Tottenham was going to hurt us. That's what they were doing. He made one run: one penalty. You've got to be clever (to do that).''