Von Miller In Good Spirits After ACL Surgery, 'Don't Feel Sorry For Me'

Take a deep breath, Bills Mafia -- Von Miller says everything is going to be okay after undergoing season-ending ACL surgery ... sending a heartfelt message to his fans from the hospital bed.

Miller posted a video shortly after the bad news broke ... saying, "Yerrr! Bills Mafia, what's good? I'm good man. I'ma be right back, man."

"Mentally, I couldn't be in a better spot and I think that is the majority of it. Don't feel sorry for me, don't say I hate it for you -- none of that stuff 'cause I am good!"

The Bills announced on Wednesday that the star pass rusher -- who signed a 6-year, $120 million contract this offseason -- is sidelined for the rest of the season due to the injury ... but Miller is already looking forward to getting back to 100%.

"I'm excited for the opportunity to show my teammates how tough I am, how hard I work, and how important that this means to me. I love you guys, and I appreciate you guys. All love and respect. Don't blink, baby!"

Miller suffered the injury against the Detroit Lions at Ford Field on Thanksgiving Day ... but the initial belief was that the 33-year-old avoided significant knee injury.

According to head coach Sean McDermott, Von checked in to the hospital for exploratory surgery ... but doctors told the two-time Super Bowl Champ that he tore his ACL instead.

McDermott called the injury a "very unfortunate situation" for Miller and their team ... adding he knows how much #40 will miss being out there with the guys.