Welker suffered two concussions in a span of four games last season. He missed the final three regular season games.
Broncos head coach John Fox said Tuesday that Welker is doing "fantastic" in his recovery from his most recent concussion.
The Broncos open the season at home against the Colts on Sept. 7.
GALLERY: NFL PLAYERS LOSING THEIR HELMETS
NFL Players Losing Helmets
The bloody scalp Eli Manning suffered in a preseason game against the Jets brought to mind just how vulnerable NFL players are after losing their helmets. Here are some other instances of helmetless players over past seasons.
- Dan Gartland