The most important detail in the ongoing contract negotiations between the Dallas Cowboys and Dak Prescott could be length. 

The quarterback could prefer a shorter contract in order to earn more in future deals, according to ESPN's Jeremy Fowler: 

"Here are the remaining issues, as I understand them. It's not simply about Dak Prescott being one of the highest-paid players on a per-year average, it's about the guaranteed money. It's about how much money he's going to get in his first two years and it's largely about how long the contract is going to be.

"The Cowboys love to typically do long-term deals, five, six, seven years. Prescott, from my understanding, does not want to be beholden to a long-term deal when he wants to get back to the negotiating table at some point." 

The NFL's implementation of a 17-game season could be one of the factors Prescott is taking into account when discussing terms with the Cowboys. 

If the 26-year-old can maximize his earnings in this current deal and then profit off another contract once more revenue streams come in over the next few years, he could end up with a hefty pay day.

Future deals for Patrick Mahomes and other young quarterbacks could also drive up the price of a future Prescott contract if he inks a four-year agreement with Dallas. 

At the moment, Prescott is under the exclusive franchise tag and in line to make $28.7 million, which would make him the ninth highest-paid quarterback in the NFL. If he wants to be in the upper echelon of average annual value, he would have to earn at least $33 million per year in his negotiated deal. 

Russell Wilson leads the league at $35 million per year, with Ben Roethlisberger, Aaron Rodgers, Jared Goff and Kirk Cousins closely behind him.

David Moore of the Dallas Morning News reported the latest offer from the Cowboys put Prescott ahead of the $32 million Carson Wentz makes per year with the Philadelphia Eagles. 

While a five-year contract would pay out more money, Prescott could still rank in the top five of average annual value if he strikes a four-year deal.

Dallas showed little hesitation working out a five-year, $100 million deal for Amari Cooper at the start of NFL free agency, so it should not have a problem spending more cash on its quarterback. 

While the Prescott negotiations have progressed, the Cowboys have been busy finalizing other aspects of their roster. 

According to Michael Gehlken of the Dallas Morning News, they signed tight end Blake Bell to a one-year, $1.7 million deal. 

The 28-year-old spent the 2019 campaign as the backup to Travis Kelce with the Kansas City Chiefs, and he would serve a similar purpose behind Blake Jarwin in 2020.

Dallas needed to add a second tight end after Jason Witten landed a one-year contract with the Las Vegas Raiders. 

With Bell in place, the Cowboys have a pair of quality tight ends and two returning 1,000-yard wide receivers in Cooper and Michael Gallup for Prescott to work with in the passing game. 

That collection of talent, combined with running back Ezekiel Elliott, should help the Cowboys remain in contention for the NFC East crown in Mike McCarthy's first year as head coach.

Follow Joe on Twitter, @JTansey90

Contract information obtained from Spotrac