Yes, Christmas is just 6 days away and unless your willing to expedite your shipping, you probably can't get this in time. However, I came across these leather football helmets, and think they are one of the best gifts I've seen for the avid NFL fan. Whatever team you like, they have it available.
The great thing about these helmets are they are unique. I didn't even know they existed. They are inexpensive. Usually run you around $35, which is in that price range for your brothers, relatives. Lastly, they are fun. They can be worn around during game time and are sturdy enough to bang around with.