Steve Keim saw what everyone saw from rookie quarterback Kyler Murray in the opener last week. Terrible play for a long while, and then an impressive rally. It made Keim think back to late December, when the then-Oklahoma QB had a rough first half against Alabama in the college football playoffs, only to come back strong. That was something the Cardinals General Manager talked to Alabama players about during the Scouting combine in February.

"You have to be physically tough to play that position, no doubt about it," Keim said Friday during his appearance on the "Doug and Wolf" show on 98.7, Arizona's Sports Station. "You have to have the skillset. But the one thing that probably doesn't get talked about enough for a quarterback is mental toughness. The guy is extremely resilient."

Keim said -- obviously -- Murray must play better early. He said he thought Murray was pressing early in the game. The interception Murray threw was a prime example, when Murray should've just thrown the ball away instead of forcing a throw that never really had a chance. "He was trying to make too many things happen by himself."

The offense overall has to be better in the red zone -- one more TD instead of short field goal wins the game for the Cardinals -- and while the comeback was nice, "we've got to finish those games." Keim was happy with the "excellent" special-teams play and thought the defense played well enough to keep the Cards in the game.

-- The GM said he wasn't surprised to hear coach Kliff Kingsbury take responsibility for the struggles. "That really resembles his personality. He is a guy who at the end of the day is very confident, but at the same time he's got a humility to him that he can grow and get better."

-- Keim lamented the loss of right tackle Marcus Gilbert to an ACL injury, not only on the field but in the locker room. But he praised fill-in Justin Murray and sounded like he could see Murray holding on to the spot.

"Justin Murray, for a guy who had been here only four or five days and to be told that you're going to start on a Friday, I thought he played about as well as he could play," Keim said. "He's got a chance ... He was a guy when we claimed him, we thought he was a really good get for us."

Overall, Keim praised the other four starters on the offensive line. "I thought we played better than probably any game last year."

-- The topic of the preseason -- and the battle whether to play more (so a team is ready for the regular season) or not (to protect from injury) -- came up. It's not just about entertainment value. A team doesn't want to get in a hole early with poor play, given that these games, win or lose, count just as much as November.

"You've got 32 people across the NFL asking the same thing, because we have to figure this out," Keim said. "You look around the league, there were a number of teams with high-flying offenses that did not execute the way they wanted to Week 1."