The No Fly Zone is in full effect and awaiting a visit from the St. Louis Rams.

The Arizona Cardinals are off to a 3-0 start and already own a two-game lead atop the NFC West as they prepare for Sunday's division matchup against St. Louis on Sunday.

A big reason for the early success is the stellar play of Arizona's secondary, which had a pair of early interception returns for touchdowns in last week's drubbing of the San Francisco 49ers, including one by reigning NFC Defensive Player of the Week Tyrann Mathieu.

More from FoxSports

The Rams are well aware of how the Cardinals' defense can change a game. Arizona capped a 21-point fourth quarter with an interception return and fumble return for TDs in a 31-14 victory over St. Louis in November 2014.

"They have two really good corners and two good safeties," Rams tight end Jared Cook said of the No Fly Zone per the St. Louis Post-Dispatch. "So they can mix guys up a lot, play guys in the box. They're very versatile in the secondary."

The Cardinals have scored an NFL-best 12 defensive touchdowns since the start of 2013, with 10 of them coming via interception returns.

"It's a high priority for us to have big plays, splash plays defensively," Arizona coach Bruce Arians said. "Negative plays creating turnovers. All our defensive backs have really good ball skills. We don't want guys who can cover but can't catch."