Welker owners, how worried at you?

Usually a concussion is no big deal, and a player will not miss significant time. But with this being his 3rd in less than a year, coupled with the NFL being extremely cautious with concussions now, how worried are you that he will:

a) miss significant time?

And

b) be less productive due to hesitancy?

I'm in a large league so starters are that much more important as we don't have many bench players, and I must say I'm fairly concerned.