Flying Artie scratched from Newmarket, replaced by Extreme Choice

Three-year-old Flying Artie will not run in the Newmarket Handicap after mucus was detected in a scope.
His Mick Price-trained stablemate Extreme Choice will now take Flying Artie’s place in Saturday’s field for the 1200m sprint at Flemington.
Hong Kong’s champion jockey Joao Moreira, who was booked for Flying Artie, will now ride Extreme Choice.
Here’s how Twitter reacted to the news this morning:
Mick Price says Flying Artie will be treated for lung infection & require 3 days in the paddock. Still hopeful of TJ Smith in Sydney @Racing
— Brent Zerafa (@brentzerafa) March 6, 2017
Feature Race: 11-03-2017 Flemington- Flying Artie -NOT ACCEPTING:degree of mucus detected on scope
— RVStewards (@RVStewards) March 6, 2017
I know Flying Artie is scratched but I can’t rule him out with Moreira on. That’s how good he’s going! #magicman
— Shane Adair (@beat_the_bagman) March 6, 2017
So, why weren't both Extreme Choice and Flying Artie scheduled to run in the Newmarket ?
— Matthew (@djebel) March 6, 2017