Díaz's wife, Nashaly, shared a snapshot of the pitcher on Instagram ... showing him throwing up a peace sign as he lay in bed with blankets draped over his legs.

Díaz -- who suffered a right knee patellar injury while celebrating Puerto Rico's win over the Dominican Republic in the World Baseball Classic on Wednesday -- also sent a message to his supporters ... saying everything is going to be okay.

"To all my beloved fans, especially the Mets fans, I want to let you know that I am doing well and healing," the All-Star said. "I feel blessed and grateful for your support with messages and prayers, thank you very much!"

Díaz -- whose game entrance has gone viral for being the most hype moment you can experience at a baseball game -- assured Mets fans they'll hear "Narco" by Timmy Trumpet and Blasterjaxx soon enough.