"Both guys finished practice," Detroit coach Jim Schwartz said. "Certainly, you don't expect those, but that's why they wear helmets. I'm glad there's not some new rule that you're not allowed to wear helmets because we might have a couple of broken jaws."
Smith was coming out of the end zone and Scheffler was running a route toward the same area when they hit each other hard.
The 6-foot-5, 255-pound Scheffler got up relatively quickly and rolled his neck as he walked back toward the middle of the field.
The 6-1, 217-pound Smith stayed down for some time before slowly standing up and limping a few steps.
"It was scary, and it hurt a little bit," Smith said. "I was feeling too good to get nicked up in practice. It's a big game Saturday."