Saints running back Khiry Robinson picks up yardage on a screen pass Sunday.

The Cardinals did an enviable job stuffing the run and blanketing receivers on Sunday against the Saints, yet still gave up 408 total yards.

The main culprit was screen and swing passes to the New Orleans running backs, as Mark Ingram – eight catches for 98 yards – and Khiry Robinson – five catches for 51 yards – combined for multiple big gains. The Cardinals were caught out of position many times because a defender rushed the quarterback instead of covering the running back when he slid out into the flat.

Coach Bruce Arians

called it a correctable mistake, and that could be determined quickly because the Cardinals will face Matt Forte on Sunday – the Bears running back with some of the best receiving skills for his position in the NFL.

"Anytime you show something on film, you are going to get it for at least a month because it's a copycat league," Arians said. "Until you put the fire out, that's all you're going to see. We have to do a better job securing that area this week and putting out the fire."

Forte had 102 receptions for 808 yards and four touchdowns last season, setting an NFL single-season record for catches by a running back. Larry Centers held the previous mark with 101 receptions for the Cardinals in 1995.

The Bears could try to replicate the Saints' success, but quarterback Jay Cutler doesn't think it's that cut and dried.

"All defenses are (susceptible to screen passes) if you can catch them in the right coverage, right blitz, but it's easier said than done," Cutler said. "These guys throw a lot of stuff at you. They have a lot of personnel groups, a lot of speed, a lot of talent on the back end in the secondary and they're not afraid to come and get you, so we will have to be on it with them."

Forte did most of his damage on the ground in last week's season-opening loss to the Packers, carrying the ball 24 times for 141 yards and a touchdown. Safety Tyrann Mathieu said wide receiver Alshon Jeffery and tight end Martellus Bennett are offensive weapons the Cardinals must keep in check, but the big key is slowing down Forte.

"We don't have to even watch film to know that," Mathieu said. "If we can stop the run and stop him in the screen game, I think we'll be pretty good defensively."

IUPATI LIMITED IN PRACTICE; ELLINGTON SITS

Mike Iupati returned to practice for the first time since arthroscopic knee surgery on Aug. 20. It was in a limited capacity, and he still may be a longshot to play against the Bears. Before practice, the Pro Bowl guard said the knee felt "great" and the Week 3 home game against the 49ers could be the target return date.

"Hopefully this week goes well, and hopefully next week I'll come back," Iupati said.

Iupati wore a brace at practice and participated in individual drills with the other offensive linemen during the portion open to the media.

Arians said running back Andre Ellington (knee) would participate in limited fashion, but he ended up sitting out. Ellington needs to practice by Friday to have a shot at playing, Arians said previously.

Wide receiver Michael Floyd (hand) practiced fully and will likely see his role expand against Chicago. Floyd had an 18-yard catch early against the Saints but only played nine snaps. Tight ends Jermaine Gresham (hamstring) and Troy Niklas (hamstring) also practiced fully.

For the Bears, defensive tackle Ego Ferguson (knee) and cornerback Tracy Porter (hamstring) missed practice. Former Cardinals linebacker Sam Acho (illness), linebacker Jonathan Bostic (ankle), cornerback Sherrick McManis (thigh) and linebacker Pernell McPhee (wrist) were limited.

MENTAL GAINS PAY OFF FOR PALMER

The main focus has been on quarterback Carson Palmer's knee this year, but after throwing for 307 yards with three touchdowns and coming away healthy against New Orleans, attention has shifted to his head.

While Palmer voraciously rehabilitated from his torn ACL to be ready for the opener, he continued to do just as much mental preparation.

"He is playing at a level mentally as well as anyone I've ever had," Arians said. "He's a gym rat. He will be bugging me all day (Wednesday) about why we are doing this one, this one, this one. It's because it's game-plan day. And he will go home and study for two hours after he puts the kid to bed."

Palmer's comfort in the offense is evident, and as the season goes on he will continue to spend hours fine-tuning his craft mentally.

"It doesn't come easy," Palmer said. "I don't have a photographic memory. I wish I did because I would have a lot more time for other things."