MMA's Khetag Pliev Back to Training Just Days After Finger Was Ripped Off!!!

MMA fighter Khetag Pliev is so tough, he's already working out again ... less than a week AFTER SOMEONE RIPPED OFF HIS FINGER!

Remember, Pliev was fighting Devin Goodale at Cage Fury Fighting Championship in Philadelphia on April 1 when suddenly everyone noticed Pliev was missing a digit!!!

People scoured the arena looking for the detached finger -- which was ultimately located inside Pliev's glove.

37-year-old Pliev was rushed to a hospital and doctors were able to successfully reattach it.

Fast-forward 6 days ... and Pliev has already resumed his training!!!

Check out the footage of Pliev getting in some cardio while his finger is stabilized with a special medical brace.

Pliev tells TMZ Sports ... he's hoping to show Dana White he's tough enough to fight in the UFC.

For the record, we spoke to Dana about Pliev's injury -- and to say Dana was impressed with his toughness is an understatement!!!