I need to add a field to a JSON response.

```
def index
    if params[:competition_level]
      @competition_level_id = params[:competition_level].to_i
    end

   @matchups = @weekly_scoreboards

   # can I call @matchups[0].as_json to return a hash, and add a field?
   # let's see...

   @matchups[0].as_json.merge!({ 'disabled' => true} )

   # this returns @matchups[0] looking the way I need it to,
   # but it I look at @matchups[0].as_json again, the field I added is 
   # gone

   respond_to do |format|
      format.html { render }
      format.mobile { render }
      format.json {
          render :json => @matchups.to_json
      }
   end
end  

```

Not sure what's going on here. Been going over this for a few hours.