Mikel Arteta has refused to use the absence of Pep Guardiola as an excuse for Manchester City's surprise defeat to Lyon in their Champions League opener on Wednesday night.
Assistant manager Arteta was taking charge of City in place of Guardiola, who was watching from the stands due to a touchline ban carried over from last year's Champions League.
City were slack in the first half under Arteta's watch, falling 2-0 behind, and only managed to pull one goal back through Bernardo Silva in the 67th minute.
Arteta would not be drawn on whether Guardiola's absence had an impact, telling Sky Sports: "I have no idea. That's something hypothetical.
"The reality is that Pep wasn't here and we lost the game. If he would have been on the touchline I couldn't say if we would have won 5-0 or lost 3-0."
Defeat is City's fourth in a row in the Champions League, but Arteta said they were "well prepared" for the match.
"We were very aware of Lyon's strengths and weaknesses. We were well prepared. We weren't prepared to be 2-0 down at the break, but you have to react," he said.
"There is zero margin for errors in the Champions League, you make a mistake and you are punished. If you don't win duels, play simple balls, you will suffer - today was another example of that."