Raging Stephen Glass questioned the mentality of the Aberdeen players after a lacklustre defeat to Livingston.
The Dons failed to put pressure on the top six as Ayo Obileye and Alan Forrest netted for the 10-man Lions, with Cristian Montano seeing red late in the game.
Christian Ramirez netted a consolation goal but the visitors couldn't rescue a point in the Premiership clash.
The fuming Pittodrie boss didn't hold back on his players as their winless run extended to four games.
Glass told Red TV: "There is no surprise, we are not surprised at what the game became, that's the disappointing thing.
"We've handled that a couple of times already, once here and once at home this season.
"There is no reason for us not to handle that other than mentality and thinking we are slightly better than we are, and not handling the ugly side of the game.
"Once we started doing that late in the game we looked like a team. We didn't look like a team early on."
As the Aberdeen players trudged off the pitch, the boos could be heard from the raging away fans making the long journey home from Livingston.
Glass added: "I think days like today you get a real jolt. It's a shock to the system coming (here), actually getting beat and the reaction of the fans; it's something you don't want to replicate.
"There is an important time of the season coming up and we need to look after it properly."