Bad news, Cowboys fans … Dak Prescott did NOT reach a long-term deal with Dallas at the deadline Wednesday — reportedly turning down over $100 MILLION guaranteed.

The superstar QB had been in contract talks with Cowboys brass all offseason about getting an extension done … but the two sides just couldn’t meet in the middle.

26-year-old Dak will now play on the franchise tag in 2020 — which locks him in as Dallas’ QB for only this season at $31.4 million.

Dallas’ final offer to Dak was set to pay the 2-time Pro Bowler between $33 and $35 million every year, with over $100 million guaranteed … NFL Network’s Jane Slater reported Tuesday.

But, Prescott reportedly wanted fewer years on the deal … and the Cowboys wouldn’t budge — so now it’ll be back to the negotiating table next offseason.

It ain’t all horrible news for either side … Dak’s still getting paid BIG money this season, and Dallas will have another year to decide if it wants to pony up Patrick Mahomes-type money for the quarterback.

And, if things are still undecided by this time in 2021 … the Cowboys have the option of franchise tagging Prescott again for roughly $37 million.

Bottom line … Dak’s rich as hell either way!