The Cardinals' offense is missing superstar running back David Johnson and the left side of their offensive line with Alex Boone and Mike Iupati out. Carson Palmer is past his prime and his receivers are banged-up.

The 49ers' defense is improved from last year and better than it showed last week against the Rams.

San Francisco's offense is a work in progress. The 49ers have scored fewer than 10 points per game during two of their three games. The 49ers' best offensive player, running back Carlos Hyde, isn't 100 percent.

The Cardinals' defense gets back linebacker Deone Bucannon for the first time this season.