The knee affected Johnson's 2013 season to the point that he had to get it drained every week for a long stretch. The finger was stuck at "90 degrees" prior to the procedure to fix it.
Johnson is not yet 100 percent recovered from the knee scope, but he expects to be there by the time training camp rolls around in late July.
"I feel pretty good right now," Johnson said Wednesday, via Fox Sports Detroit. "I'm out here working, taking all my reps for the most part. Knee's feeling good, hand's feeling good. I can't complain."
"You've got to be careful not to be a fan when you're watching him," Lombardi said. "It's really unbelievable when you see him in person, just how big and strong and fast he is."