To say that the Dallas Cowboys [VIDEO] underachieved in 2017 is an understatement of epic proportions. On the heels of a 13-3 season, and being tagged as one of the top three favorites to win Super Bowl 52, Dallas stumbled out of the gate last September and never recovered. Worst of all, they watched division rival Philadelphia win the Super Bowl. So have the Cowboys improved this offseason?

Defense - the Sean Lee factor

Sean Lee is one of the best, yet somehow still underrated linebackers in the game, and Dallas Cowboys fans know how important it is to have him in the lineup. The number differential for Dallas when Lee is in the lineup compared to when he is out is incredible.

According to Cowboys Wire, Lee missed two parts of the 2017 season, with one coming early in the year and then once again when Dallas was already without Ezekiel Elliott and Tyron Smith. The effect of his absence was huge, to say the least. In the seven games where Lee was out of the lineup, the defense allowed over 27 points per game. They allowed just 15 with Lee in the lineup.

Even though Dallas has added a few key players to the defense for the 2018 season, Lee is their field general and they need him to be on the field more than off. Dallas did add Kony Ealy [VIDEO] this offseason and they are reportedly eyeing linebackers Vita Vea and Maurice Hurst [VIDEO]in the upcoming draft.

Dak Prescott, Ezekiel Elliott combo

The other factor Dallas needs to improve is the offense. Okay, while that is a very general statement, let’s put it this way, there is a lack of creativity on offense.

Two seasons ago the Dak Prescott, Ezekiel Elliott combo was incredible. Year two was not.

In fairness, Zeke was missing for half the season and Dallas’ running game became almost nonexistent. This season, there won’t be room for excuses. Opposing defenses know that if you slow down Zeke, Dak can get flustered and make bad decisions. The Cowboys need to up their game in 2018, especially now that the Eagles have "storm-troopered" the NFC East.

Last season Dallas finished 14th in yardage and 14th in scoring, which sounds okay. However, a lot of yardage and points came in mop-up situations. OC Scott Linehan and Jason Garrett are going to have to get on the same page to make things work in 2018. Sure, having Zeke in the lineup is key, but having a trick play or two on standby is crucial to keep an offensive drive going.

Dallas added new offensive coaches in Paul Alexander, Sanjay Lal, and the well-traveled offensive minded Doug Nussmeier to the 2018 roster this offseason with hopes of tweaking things up a bit. However, it is still on the players to carry out the execution on the field. Adding a stud like Alabama’s Calvin Ridley to the offense this season would be a big help as well.