Thomas Tuchel declared Chelsea must improve "as fast as possible" after claiming "it does not take a lot" to beat the Blues at present after their underwhelming Premier League start continued at Southampton.
Chelsea took the lead through Raheem Sterling on Tuesday, but goals from Romeo Lavia and Adam Armstrong turned the contest on its head as Southampton secured a 2-1 success.
Having been thrashed 3-0 by Leeds United on their last road trip, Chelsea have now suffered back-to-back away league defeats for the first time since December 2020.
Tuchel, meanwhile, has suffered consecutive league losses on the road for the first time since he was coaching Paris Saint-Germain in August 2019.
After Southampton moved level with the disjointed Blues in the early-season Premier League table, Tuchel was at a loss to explain their troubles.
"I don't know if concerned is the word, I absolutely dislike to lose and it's the second time in the season, very early," he told BT Sport.
"I think it does not take a lot to beat us. This is what I don't like. We are humble enough to understand that we can lose matches and of course, away matches.
"We don't like it and we try to win every match but the way we do this is something we need to understand as fast as possible and to change.
"It's difficult, I don't know why, we start well in all the games almost, and obviously we struggle with our focus and consistency in matches.
"It's not enough to play 20 minutes good, we did the same in Leeds. Then one thing goes against us, and we struggle to find answers and fight our way back if things don't go in our direction."
Meanwhile, Sterling has now scored each of Chelsea's last three goals, and while Tuchel is concerned by his team-mates' attacking struggles, he emphasised the importance of rediscovering their defensive composure.
"It is what it is and it's the reality. We played with four offensive players now many, many times," Tuchel said.
"I think in the first 20 minutes we created chances, half-chances but we struggled to score, which is also not brand new for us and does not necessarily need to have the consequence that you lose matches.
"You can also win 1-0 or 2-0 with a late goal, so no problem. But then you need to have a clean sheet, you need to be more focused.
"The amount of individual errors, the lack of concentration is simply too high at the moment to win football matches consistently. We can win, of course, but it's not consistent enough."
Chelsea were without Reece James due to illness and the injured N'Golo Kante on the south coast before sustaining another blow when Ruben Loftus-Cheek was withdrawn at half-time after suffering discomfort.
Tuchel was visibly frustrated with the injury woes that have hampered Chelsea as he added: "It's a hamstring injury, so the next midfielder is out and nobody is left.
"The recommendation for Mateo Kovacic was 20 minutes, we made 45 out of it. That's the situation.
"I also don't understand why we are in this situation regarding the injuries, and the injuries like all players in midfield. But that's the way it is, and we need to find solutions."