Five things I noticed about the Cardinals in the first half of Sunday night’s game against the Cowboys:

Defense impresses

The defense was a disappointment last week against the Saints, but it was much better against the Cowboys. Sure, it helped that Dallas didn’t play many of its starters, but at least the Cardinals did what they were supposed to do.

Coordinator Al Holcomb called several blitzes early and gave us a preview of how he’s going to use linebackers Josh Bynes and Deone Bucannon. Both played for the first time this preseason and regularly blitzed on Sunday. Bucannon had three tackles and a sack in the first two series.

Cornerback Patrick Peterson blitzed once early in the game, and then he returned an interception for a touchdown late in the first quarter.

Turning it over

The Cowboys committed five turnovers in the first half. Peterson forced two of them, including the interception and a fumble. The Cowboys muffed two punts, including one Cardinals rookie Trent Sherfield recovered in the end zone for a touchdown. Safety Budda Baker intercepted a pass in the end zone late in the first half. It was the 13th turnover committed by Cardinals opponents this preseason.

It’s a good sign for the Cardinals, who were minus-4 in turnover ratio a year ago.

Offensive tackles struggle

Left tackle D.J. Humphries struggled with defensive end Randy Gregory and gave up a sack early. Right tackle Andre Smith was beaten by Demarcus Lawrence, who hit quarterback Sam Bradford as he threw.

That’s especially troublesome because it’s not as if Bradford is taking a lot of time to get rid of the ball.

Can anyone catch?

Receiver J.J. Nelson dropped a pass. So did receiver Christian Kirk. Tight end Ricky Seals-Jones had a reception knocked from his hands by a defender. All that happened in the first quarter. Bradford completed just 1 of 4 passes for 6 yards before leaving midway through the quarter.

Kirk dropped a perfect throw by Mike Glennon.

This receiving corps is a big question mark, even more so after a shaky first quarter.

Who didn’t play?

Receiver Larry Fitzgerald, running back David Johnson, quarterback Josh Rosen and the team’s top three defensive tackles didn’t play.

Robert Nkemdiche, Corey Peters and Olsen Pierre are expected back by the regular season.

Fitzgerald and Johnson are fine; they’re just being shut down for the preseason. Rosen hit his right thumb on a helmet in practice last week, and coach Steve Wilks apparently didn’t think it would be smart to play Rosen at less than 100 percent.

The Cardinals probably won’t play their starters in the preseason finale Thursday night against the Broncos in Glendale, but the guess here is that Rosen gets some work, as long as the thumb is fine.

With Rosen out, Mike Glennon replaced Bradford and did a decent job. His first four completions gained just 9 yards, but he was victimized by Kirk’s drop.

The backup running back

Coach Steve Wilks doesn’t gush often about players, but he’s complimented rookie running back Chase Edmonds often this summer.

You can see why. Edmonds started in place of Johnson and gained 55 yards on 11 carries in the first half, with a long of 28.