The Dallas Cowboys got their season off on the wrong foot with an ugly 28-20 loss to the New York Giants on Sunday night.The Cowboys entered this game with renewed hope on the defensive side of the ball after a busy offseason, but it would appear that hope was misplaced after what we saw in Week 1.The Cowboys' offense did not look like the elite unit we expected it to be and one major fear we had all offseason long reared its ugly head.We'll go over those issues and more as we take a look at the biggest takeaways from Dallas' season-opening loss to New York.Same old defenseDallas Cowboys defensive coordinator Christian Parker at training camp at River Ridge Playing Fields. Mandatory Credit: Kirby Lee-Imagn Images | IMAGN IMAGES via Reuters ConnectThings were supposed to be different for the Cowboys' defense this season after a total overhaul during the offseason.However, if we didn't know any better, we would have thought nothing changed for Dallas' unit.The Cowboys played way too much soft zone and the Giants were able to pick it apart, especially with Dallas not generating enough pressure, and that led to New York converting on 10-of-11 third downs.There was no resistance from the run defense, either, and tackling was poor.As if all that wasn't enough, there were communication issues that further stacked the deck against Dallas' unit.There's still a long way to go this season, but this was not a good start for Christian Parker and the Cowboys' defense.Too many self-inflicted woundsNew York Giants safety Jevon Holland (8) celebrates an interception against the Dallas Cowboys during the second quarter at MetLife Stadium. Mandatory Credit: Brad Penner-Imagn Images | IMAGN IMAGES via Reuters ConnectThe Cowboys playing poorly in general made things difficult enough, but they set themselves back even further with so many self-inflicted wounds.The Cowboys committed seven penalties for 60 yards in the first half alone, which is particularly frustrating after Dallas was the most penalized team in the NFL last season. The seven first-half penalties were the most the Cowboys have tallied over the first two quarters of a game since 2008.Dallas cleaned it up in the second half with two penalties, but one came on a taunting from Javonte Williams that led to a missed extra point, and the other came on a facemask that handed New York a crucial first down late in the fourth quarter.Dak Prescott threw an ugly interception and George Pickens dropped two passes, one of which could have resulted in a long touchdown, and CeeDee Lamb dropped another.Too much pressureDallas Cowboys quarterback Dak Prescott (4) passes the ball against the New York Giants during the first quarter at MetLife Stadium. Mandatory Credit: Vincent Carchietta-Imagn Images | IMAGN IMAGES via Reuters ConnectOur fears about the Giants' talented pass-rush wreaking havoc on the Cowboys' suspect offensive line came to fruition.Prescott was under pressure far too often, and especially in the first half, when Prescott was pressured on 10 of his 19 dropbacks and was 3-for-9 for 23 yards with a pick.What's even worse, the Giants were able to do all that without sending extra rushers, which allowed them to drop more help into coverage.The offensive line was the subject of concern coming into this season and this performance, both in pass protection and run-blocking, did nothing to quell that.Where's the adjustments?Dallas Cowboys head coach Brian Schottenheimer looks on during the second quarter against the New York Giants at MetLife Stadium.cc. Mandatory Credit: Brad Penner-Imagn Images | IMAGN IMAGES via Reuters ConnectThe lack of adjustments throughout the contest were frustrating, to say the least.To combat the pressure on Prescott, the Cowboys could have called for more screens. We also wanted to see the Cowboys make it a point to get the rock to Lamb and Pickens more by any means necessary.Abandoning the soft zone would have been a good idea, too, and trying to bring more blitzes should have been added to the game plan with the lack of pressure on Dart.There was also the infuriating fourth-quarter scoring drive for the Giants in which they kept dumping the ball off to their backs with constant success and Dallas did nothing to attempt to combat that.This loss was as much on the coaches as it was on the players, plain and simple.Missed opportunitiesNew York Giants running back Cam Skattebo (44) carries the ball against the Dallas Cowboys during the third quarter at MetLife Stadium. Mandatory Credit: Vincent Carchietta-Imagn Images | IMAGN IMAGES via Reuters ConnectThe Cowboys managed to force one turnover when Shavon Revel recovered a fumble, but they could have had more.The Giants fumbled the ball a total of four times throughout the game, yet they were able to recover three of them. Dallas finished with the third-fewest turnovers in the league last season and we didn't see a sign that things will improve this season.—Sign up for the Cowboys Daily Digest newsletter for more free coverage fromDallas Cowboys on SI—Add us as a preferred source on GoogleFollow