ALLEN PARK -- Glover Quin's streak might live on after all.
The Detroit Lions safety missed the first two days of practice this week due to a concussion, but was back on the field Friday as the team made its final preparations for Sunday's home finale against the San Francisco 49ers.
That suggests he's in either Step 4 or Step 5 of the return-to-play protocol, and puts him in a position to play Sunday.
"We'll see," coach Jim Caldwell said. "He's coming along."
The steps for returning from a concussion are, according to team trainer Kevin Bastin:
Step 1: Become symptom-free
Step 2: Begin light exercise
Step 3: Go 100 percent for a cardio workout
Step 4: Practice without contact
Step 5: Practice with contact
Final step: Independent neurologist grants approval to return
Quin suffered the concussion in the first half of Monday night's win against the Saints.