The son of former Aberdeen and Falkirk striker Lee Miller has already made 76 senior appearances.
He was a near ever-present last season as Motherwell finished eighth in the Scottish Premiership, scoring four goals in his 41 appearances and earning his first two Scotland caps.
Asked about Miller’s absence on Saturday, Askou said: “Yes, it was a final call with everything taken into consideration.
“It’s not a secret that there are things going on in the background. We know he’s been out for four weeks.
“How much risk are you willing to take on a player like him in that situation? The decision was that we kept him out of it.”
