The Aberdeen youth product had to fill the gaps left by missing midfielders Robson and Flood during the Reds' 3-0 win over Partick Thistle.
And classy Jack produced a composed performance in the centre of the pitch, earning rave reviews and calls for a Scotland senior squad berth.
Now AFC boss Derek McInnes has joined those heaping praise on the former Scotland Under-21 captain, naming him one of the best in the league.
McInnes said: “Ryan is as good as anything going about in the Scottish Premiership.
"I see him as one of the main midfielders at the club who will get even better in years to come."