What happened to Andy Dalton? Why Cowboys' new QB left Bengals to back up Dak Prescott

The Cowboys were unable to sign Dak Prescott to a long-term contract this offseason,and the fifth-year quarterback will become an unrestricted free agent in 2021 if no deal is reached after the 2020 season.

But Dallas did sign another veteran quarterback in the offseason as insurance.

Andy Dalton, who spent the last nine seasons in Cincinnati, signed a one-year, $3 million dealwith the Cowboys to back up Prescott. Dalton left the Bengals after they drafted Joe Burrow with the No. 1 pick in the 2020 NFL Draft.

That will add to the intrigue in Mike McCarthy's first season as head coach.Here is a look at how that could unfold.

MORE: Ranking NFL QBs from best to worst in 2020

Why did Andy Dalton leave the Bengals?

Joe Burrow is the easy answer, but that departure was building last season. First-year coach Zac Taylor benched Dalton after an 0-8 start, but the veteran quarterback returned and led the Bengals to a pair of late-season victories.

Dalton's career in Cincinnati is underappreciated. The three-time Pro Bowl selection had a 70-61-2 record as a starter. The Bengals made five straight playoff appearances from 2011-15. Dalton was 0-4 with one TD and six interceptions in four playoff starts.

To be fair, Dalton led the Bengals to a 10-3 record as a starter in 2015 before he suffered a broken thumb against Pittsburgh. A.J. McCarron started in the AFC wild-card loss to the Steelers later that season.

Dalton turns 33 in October, and this is his first season as a full-timebackup.

Will Dak Prescott lose his starting job?  

Please get past the subhead. The answer is an emphatic “no.”

Prescott is coming off a career year in which he passed for 4,902 yards and 30 TDs. He has compiled a 40-24 record the last four seasons as a starterfor the Cowboys. Dallas has reached theplayoffs twice in the last four seasons.

Prescott also is working with a talented group of receivers thatincludesAmari Cooper, Michael Gallup and first-round pickCeeDeeLamb.

The Cowboys have never finished below .500 with Prescott, but last year's 8-8 record, Jason Garrett's exit after 10 seasons as head coach and the ongoing contact talks are all hot topics in Big D.

Cowboys fans can relate to Dalton 

Dalton is a Katy, Texas, native who had successful careers at the high school and college level in the state.

He led Katy to a state championship game appearance in 2005, and he followed that up witha banner career at TCU. He was 42-8 as the starter for the Horned Frogs, and that included a perfect 12-0 season with a Rose Bowl victory against Wisconsin in 2009.

The Bengals drafted Dalton with a second-round pick in 2011.

Is Dalton the best backup QB in NFL?  

The Saints signed former No. 1 pick Jameis Winston in the offseason, and that's the only backup quarterback ranked higher than Dalton inNFL.com's rankings.

Nick Foles and Joe Flacco also are backups in 2020, and they have won Super Bowls.

Dalton is at least one of the most-reliable backup QBs in the NFL given his experience in Cincinnati.

Why is Dalton's presence important?  

Prescott is the starter, but the contract talk is not going away. The relationship between McCarthy and Prescott is going to be over-scrutinized as a result, and the Cowboys always operate under the shadow of longtime owner Jerry Jones.

If the season does not go well, the speculation will turn to whether Jones will make a play for one of the elite quarterbacks in the 2021 NFL Draft. That class includes Trevor Lawrence, Justin Fields and Trey Lance.

Again, that is speculation, and analysts such as First Take's Skip Bayless likely will ramp that up throughout the 2020 season.

Dalton's role as a backup likely will not change unless there is an injury, but he has hidden value in that position for this season, and perhaps the future.