EXCLUSIVE

Back up off that ledge, Knicks fans -- Dr. Oz says Kristaps Porzingis can get 110% better from his torn ACL ... if he takes his advice.

We got doc Oz out in NYC ... and he broke down why Kristaps' season-ending injury ain't the end of the world (just the Knicks' season). 

Don't get it twisted -- the celeb surgeon told TMZ Sports Porzingis is gonna have to bust his ass in rehab ... but if he follows a few of his recovery tips, Oz says he can legitimately "come back better than ever before."

Get well, KP!