Mikel Arteta refused to use the absence of Pep Guardiola as an excuse after Manchester City suffered a shock loss to Lyon in their Champions League opener.

City boss Guardiola could only watch from the stands due to a touchline ban as City were beaten 2-1 in the Group F encounter at the Etihad Stadium.

The hosts were punished for mistakes as Maxwel Cornet and Nabil Fekir struck in the first half and they could not recover despite being given a lifeline by Bernardo Silva after the break.

Asked if City’s performance might have been different with input from Guardiola, assistant boss Arteta said: “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 0-3.”

Pep Guardiola was forced to watch from the stands after being sent off against Liverpool last season
Pep Guardiola was forced to watch from the stands after being sent off against Liverpool last season (Martin Rickett/PA)

City had been installed as competition favourites prior to the group stages getting under way but Arteta conceded the team were not up to standard.

He said: “We started a bit slow, we weren’t consistent in the way we tried to play.

“We gave the ball away in the build-up in difficult circumstances and they took advantage and scored twice. At this level, it’s not good enough.

“You have zero margin in the Champions League. When you make mistakes, you get punished.

“Whether it is a lack of attention, not winning the duels, losing simple balls or not being effective enough, you pay the price and today is another great example of that.”

Arteta was asked in his post-match press conference if he thought the atmosphere was poor but insisted that was not an issue.

He said: “I wouldn’t like to use that as an excuse because we had that type of crowd in the Champions League before and we were able to win.

“The ideal scenario is to have a full stadium every time and being behind the team like crazy but we know sometimes it doesn’t happen. I don’t think that’s an excuse though.”

Defender John Stones admitted City are already playing catch-up in the group ahead of their next game against Hoffenheim – who began with a draw against Shakhtar Donestsk – in a fortnight.

Stones told BT Sport: “We’re really disappointed. To concede two goals like we did was very frustrating, especially in first half.

“It’s the first game, it’s still early days. We put pressure on ourselves to go win the next game. There’s no outside pressure, we know our own strengths.”

Lyon coach Bruno Genesio felt his side were full value for their victory.

Genesio said: “It’s a great achievement and a deserved one. We were very, very good in the first half defensively and we also created chances.

“We had an opportunity to make it 3-0 that I think would have completely killed the game off.

“We suffered a bit towards the end of the game as their changes meant they had more pace on the pitch and they upped their rhythm. We stayed solid and worked for each other. We won and that’s hugely satisfying.”