The Titans have just canned their head coach, according to multiple reports ... after he spent the last six seasons roaming the sidelines in Nashville.

The final decision came down less than 48 hours after the Titans' 28-20 upset win over the Jaguars on Sunday.

Vrabel started his Tennessee tenure with a bang ... logging winning seasons in his first four years -- though things have gone a bit south in the past two.

In his last 34 games, he's recorded just a 13-21 record ... and their offense has sputtered.

A lot of change is on the horizon in Tennessee -- star running back Derrick Henry is a free agent this summer. He was a big part in Vrabel’s playoff runs in Tennessee, but gave what felt like a farewell speech following their win.

Titans owner Amy Adams Strunk addressed the move on Tuesday ... saying, "Earlier today, I spoke with Mike Vrabel and told him about my decision to make a change at head coach."

"As I told Coach Vrabel, this decision was as difficult as any I've made as Controlling Owner. I appreciate Mike's contributions to the Tennessee Titans both on and off the field."

"Anyone who has ever met him knows how passionate and genuine he is, and he's been a strong supporter of the Nashville community," she added. "We wish Mike, Jen, and the Vrabel family nothing but the best in the future."

Vrabel -- the third-winningest coach in Titans history -- will almost certainly land on his feet somewhere -- the former New England Patriots star is widely respected around the league and is already viewed as a potential candidate for current head coaching vacancies.

In fact, most think if Bill Belichick leaves Foxborough this offseason, Vrabel could be the ideal man to replace him.