The Gunners lost for the second successive game in the top flight this season as they were bullied on their own turf and succumbed to first half goals from Romelu Lukaku and Reece James.
With a trip to champions Manchester City next on their agenda, Arsenal could head into the first international break of the season without a point to show for their efforts.
Mikel Arteta’s side find themselves in the relegation places at this embryonic stage of the season despite being the biggest spenders of any Premier League side this campaign.
Sagna, who starred for seven seasons at the Emirates Stadium and won an FA Cup, was less than impressed with Arsenal’s performance against the European champions and has slammed his former side for only investing in youth rather than experience.
‘When I watch Arsenal now, honestly, I know that they are going to lose the majority of the time, that something is going to happen, that we are going to concede a stupid goal,’ Sagna told RMC Sport.
‘How can you spend €150million and only bring in young players? It might be good for the future, but someone has got to think about the present.
‘When I was playing, anyone would be excited to join Arsenal, now we have lost our DNA.'
The former France international added: Maybe we have players with character but they have won nothing. Today, you know how youngsters are, some older player tells them what to do.
'They say, "well, what have you won?". A player who has won titles barely has to speak to be listened to.’
