Captain Smith said guys who were in form were being given space in the team.
He said Renshaw was overlooked by the selectors because he hasn't been able to get runs on the board.
"He [Renshaw] unfortunately hasn't been able to get the runs on the board that the selectors wanted, and the Ashes isn't a place where you need to be trying to find your form. I think it's great what the selectors have done, they've gone with the guys that are in-form and if the top six are getting big runs for us, I'm confident our bowlers can do the job," the Australian skipper said.
On Tim Paine, Smith said, "His inclusion may have come as a surprise to a lot of people but I'm excited what he brings to the team. I'm sure he'll do a terrific job for us."
The 13-men squad also includes Mitchell Starc, Pat Cummins and Josh Hazlewood as bowlers.
The Ashes series begins from November 23 in Brisbane. (ANI)