Knowshon Moreno: I Wanna Play for the Broncos Again ... I Feel Good, Healthy

Knowshon Moreno says he's laser-focused on an NFL comeback -- with the running back telling TMZ Sports he's healthy and ready to go ... and would love to return to his old team in Denver.

The 28-year-old -- who hasn't played since suffering an ACL injury in 2014 -- appeared on the "TMZ Sports" TV show on FS1 and discussed his comeback plans.

"I still have a lot in the tank ... probably TOO MUCH in the tank! I have to let it out!"