PHILADELPHIA -- Eagles quarterback Nick Foles' biggest mistake so far this season might be setting unreasonably high expectations for himself.

Foles has been so good, so statistically close to flawless, that it is easy to forget he hasn't started a full season's worth of games yet. He is 23 and still facing new challenges and unfamiliar situations almost weekly.

That's why it isn't a criticism of Foles to suggest that the Eagles' second-half offensive troubles Sunday against Arizona had more to do with the quarterback than with Chip Kelly's play calling.

#9 QB

Philadelphia Eagles

2013 STATS

Att 196

Comp 124

Yds 1791

TD 19

Int 0

Rat 125.2

On three possessions in a row, with a 24-14 lead, Kelly remained aggressive with his play calling. Foles simply didn't throw the ball very well on several plays. He was under intense pressure on a few others.

After the Cardinals scored to make it 24-14, the Eagles got the ball back on their 29-yard line. The first-down call was for a pass to DeSean Jackson, who was running a shallow crossing route from right to left. Jackson was wide-open.

Last week, Kelly was asked whether those flyswatter contraptions in practice could help explain how Foles had avoided having a single pass batted at the line of scrimmage. Well, Calais Campbell didn't have a flyswatter, just a long reach. He smacked Foles' low throw away.

After a LeSean McCoy run was stuffed for a 2-yard loss, Foles dropped back to pass again. This time, linebacker Daryl Washington blitzed behind two linemen, sliding off and making a beeline for the quarterback. Foles stepped to his right and into the arms of Matt Shaughnessy for the easy sack.

A Cary Williams interception gave the Eagles the ball at their own 49 with 51 seconds left in the third quarter. Not only did they fail to take advantage of the field position, they had to punt on the first play of the fourth quarter. They took less than a minute to go three-and-out.

The first two plays were both passes. Foles missed Brent Celek, who had a step on safety Yeremiah Bell. A better throw and the Eagles are nearly in field goal range with a first down. On second down, Foles overthrew McCoy on a swing pass to the right. Kelly called a run on third down, and the Eagles punted again.

The final relevant sequence came on the Eagles' first possession of the fourth quarter. It was still 24-14. They needed to move the ball and score or at least kill a chunk of the remaining time. They used just under two minutes.

Foles threw two deep balls on this possession. On the first play, from his own 36, he had tight end Zach Ertz matched up one-on-one with safety Tyrann Mathieu down the left sideline. Foles overthrew Ertz when a back-shoulder throw might have gone for a long gain. Ertz made a great effort, nearly catching the ball by diving forward.

After getting a first down at the Arizona 46, Foles went deep down the left sideline again. This time he had Riley Cooper matched up with cornerback Jerraud Powers. This time, Foles underthrew the receiver. There was contact as Cooper tried to fight his way back. He got his hand on the ball, but couldn't gather it in. The TV cameras caught Cooper on the ground, looking up at an official and saying, it appears, “He grabbed my arm.”

The next two plays were pass calls. Foles was sacked both times, as unblocked Arizona defenders blitzed him and forced him into the arms of teammates.

Three of the Cards' five sacks took place during those three possessions. Foles and the offensive line, usually so adept at reacting to blitzes, were overcome by the pressure. On the next series, Foles was hit as he threw the interception that was negated by a penalty. Frequent hits will do that to even the most experienced quarterback.

Foles is not that, not yet. The Arizona defense raised its game in the second half, desperately trying to get back into a game with huge playoff implications for the Cardinals. Defensive coordinator Todd Bowles was more aggressive, taking risks in order to stop McCoy and create turnovers.

“People aren't playing the normal defenses they normally play in the first, second and third quarter,” Kelly said. “They're putting an extra guy on the line of scrimmage. If you bring in an extra tight end, they're going to have two more than you -- one for the quarterback and one for the extra player. That is a difficult situation to run the ball against. The answer is easy: Hey, throw it. If you throw it and it's incomplete, the clock stops.”

When Foles threw Sunday, it was incomplete. With experience, he will get a better feel for how to deal with situations like that. For now, he handled it well enough to avoid killer mistakes and secure the win. That's good enough.