The Cardinals are counting on QB Carson Palmer (3) and the offense to be much improved in 2013.

Ryan Williams knows he hasn't been in the NFL that long and only has been around so many coaches in his football life.

But the running back thinks about what new coach Bruce Arians has brought with his offense, and Williams bursts with optimism.

"I've never been around a coach that understands offensive football as much as B.A.," Williams said. "It's like he's a genius almost. He knows where everybody is supposed to be, anything and everything. He knows what will make you better at doing it."

In many ways, the entire Cardinals' overhaul this offseason began with the need to energize the offense. Arians, with his background as an

offensive coordinator, was hired. The team traded for quarterback Carson Palmer, signed new running back Rashard Mendenhall, upgraded its offensive line – all in an effort to avoid a repeat of last season, when points were often much too hard to come by.

Often during the offseason, the learning curve was cited. Wide receiver Larry Fitzgerald, among others, was trying to learn multiple positions. Arians would talk about the mental errors that needed to be erased. In the preseason, the coach shook his head at struggles in the red zone.

As the games that count approach, however, confidence is obvious.

"I don't think anything is ever completely automatic," Palmer said. "But I'm as comfortable as I can be to this day with putting this offense in back in April."

Added Palmer, "We are in a good place."

Palmer knows the offense won't look the same against the Rams in St. Louis Sunday as it will, for instance, in Jacksonville in mid-November. The offense is all installed, though. And as Arians has been telling his team often, "We'll throw it against the wall and just keep throwing it against the wall and see what sticks."

Some of the preseason hiccups will be shoved to the side, Arians said, because instead of digesting 300 plays for a game there will be 80 or 90 specific to each week's game plan. The narrowing of the focus can only help.

"When it is condensed like that, you can play fast instead of always having to think," wide receiver Michael Floyd said. "I can just react now, play faster. I think this offense works well for me."

The Rams have a defense that is fast, with a pass rush that piled up 11 sacks in two games against Arizona last year (including nine in the game at St. Louis.) But that was a lifetime ago, with a group that ended up scoring just 250 points all season (and 48 came in one game, against the Lions.)

Rams coach Jeff Fisher said the Cardinals have "settled into a difficult scheme to defend" and if the passing game alone can create some fear throwing to Floyd and Fitzgerald, the offense will be much further ahead of where they were.

"We are excited as a defense knowing we have a quarterback who can put points on the board," cornerback Patrick Peterson said.

That was always the plan.

"Coaching can only go so far," Williams said. "But if we execute, I feel we have the players to make (Arians') visions come alive on the field."