Colts' revamped starting defense mauled in loss to Cowboys

The good news is that the Indianapolis Colts forced two turnovers on defense against the Dallas Cowboys. The bad news is the Colts' first-team defense, the unit that was reshaped during the offseason, was dominated by the Cowboys' top offensive unit during a 24-19 loss to Dallas on Saturday night in Arlington, Texas.

Colts general manager Chris Ballard put a premium on improving the defense, as the team drafted or signed 13 players for that unit after finishing 30th in total defense last season. Saturday was the first test the Colts would face in consecutive weeks, because the Cowboys finished fifth in total offense last season.

On Dallas' first possession, receiver Dez Bryant beat Colts cornerback Vontae Davis for a 32-yard touchdown to cap off what was an easy seven-play, 95-yard drive. Dallas appeared to be on its way to easily scoring again on its second drive when linebacker John Simon and safety Matthias Farley hit Cowboys Darren McFadden to cause a fumble at the Colts’ 7-yard line. Davis recovered the fumble.

Despite that big play, it's clear the Colts still have a lot of work in front of them to improve on defense. Indianapolis gave up 166 yards and nine first downs on the Cowboys’ first two possessions. What made it even worse on those two drives is that the Colts had their projected regular-season starting defensive lineup on the field, with the exception of rookie safety Malik Hooker (shoulder).

QB depth chart: Scott Tolzien, starting in place of the injured Andrew Luck (shoulder), got off to a slow start, as the offense didn’t pick up a first down until its third series. Tolzien wasn’t flashy, but he did bounce back from a subpar preseason opener to go 10-of-14 for 70 yards while playing the entire first half. Tolzien continues to be conservative in the passing game, as he averaged just 5 yards a completion. His longest completion was 25 yards to receiver Kamar Aiken off play-action. Phillip Walker, an undrafted rookie out of Temple, was 5-of-7 for 33 yards while continuing to play ahead of Stephen Morris.

When it was starters vs. starters, the Colts looked ...: The Colts struggled to move the ball offensively. They gained only 104 yards of total offense and picked up just five first downs in the first half, including none in the first quarter. Including the preseason opener against the Detroit Lions, the Colts' first-unit offense has totaled just 125 yards and 3 points. The offense continues to be without Luck and has only one more game -- Aug. 26 at Pittsburgh -- to get it going, because the starters aren't expected to play in the preseason finale against Cincinnati on Aug. 31. The starters routinely play into the third quarter in the third preseason game.

One reason to be concerned: The Colts were expected to have troubles in the pass-rush department as they search to find the next Robert Mathis. But evidently they have issues when it comes to stopping the run, too. The Cowboys had no problems finding running lanes, rushing for 160 yards.

Rookie watch: Running back Marlon Mack didn’t disappoint in his debut. The former University of South Florida standout showed why the Colts selected in him the fourth round. Mack finished with team-high 45 yards on just five carries. Not only does Mack have the potential to be Frank Gore’s replacement down the road, but his explosiveness gives the Colts a dimension that’s different from what Gore and Robert Turbin offer in the backfield. A key for Mack going forward is that he must prove he can pass protect the quarterback, so that he can be kept on the field on third down.

Hunt goes hunting: Margus Hunt may not have much impact on the Colts defense, but he could end up playing a major role on special teams. Hunt blocked a 45-yard field goal attempt in the third quarter. At 6-foot-8, he blocked three field goals while he was with the Cincinnati Bengals last season.

Morris impressive: The reason why Morris is behind Walker on the depth chart, and why he hasn't been given the opportunity to push Tolzien for the starting job, continues to be a mystery. Morris was effective in the fourth quarter for the second straight week. He was 11-of-15 for 111 yards and a touchdown to bring his two-game preseason total to 24-of-35 for 205 yards and a touchdown.