Niall Quinn bemoaned Manchester City's 'lack of craft and savvy' after they were beaten 2-1 in the Champions League by Juventus.
A Giorgio Chiellini own goal put City ahead in the Group D opener but last season's runners-up replied with strikes from Mario Mandzukic and Alvaro Morata.
The result again raises questions over City's ability to adapt to European competition after such an impressive start in the Premier League.
"It's that lack of craft and lack of savvy that Manchester City just don't have in Europe," said Quinn.
"It's tough to watch it. We saw them play so well at the weekend [against Crystal Palace] and since the start of the season with all of their great players, but the fright set in and Juventus took advantage of it.
"Overall I think the story of the game is City have so much to learn about competing against the better teams in Europe."
Manuel Pellegrini's side went into the clash on the back of five straight league wins without conceding a goal.
Juventus, by contrast, had taken just a point from three Serie A matches, but were still able to largely contain City and take all three points.
"We got an abject lesson in City's shortcomings and frailties," said Quinn. "Juventus have given an exhibition of European professionalism, Champions League professionalism, and Manchester City's great start to the season is in tatters.
"You lose your first game at home and you have all the questions again… the good start to the season seems a distant memory. Tonight is tough for Man City to get over."
City will be hoping for a better outcome when they travel to Borussia Monchengladbach in a fortnight. The German side were beaten 3-0 by Sevilla in their opening group game.