Graham Potter felt Chelsea lacked the quality to get themselves back in the game against Newcastle United.
Chelsea managed just two shots on target as Joe Willock's stunner earned Newcastle all three points in a 1-0 win at St James' Park on Saturday.
The closest Potter's side came was Conor Gallagher forcing a decent stop from Nick Pope, with their 17 goals in 14 Premier League this term their fewest at this stage of a season since 2015-16, when they went on to finish 10th.
Potter becomes the first Chelsea manager to lose three straight league matches since Jose Mourinho in 2015, and the former Brighton and Hove Albion boss was frustrated with his team's attacking display.
"There were too many errors," Potter told Sky Sports. "We had the quality to play through but lacked that last bit.
"Newcastle are very confident. We got back into it a bit second half with Conor's effort but then they scored. They put you under pressure with high intensity.
"We tried but in the end lacked the quality to get the goal we needed. We need to do more to come away to say we deserved anything."
Potter responded to Willock's goal by using his three remaining substitutions, bringing on Hakim Ziyech, Marc Cucurella and Kai Havertz.
Potter felt these changes were needed and that they did have a positive impact, even in defeat, adding: "We had to make the change in the second half as they were overrunning us.
"We needed an extra man in midfield. We responded quite well. As soon as we are 1-0 down it is about fresh legs.
"It was a tight game, [with] not many chances. This is a tough place to come. It is not nice for us. We are in a bad moment."
This string of losses has come in the final three league games before the Premier League pauses for the World Cup.
Potter will use the break to take stock of his opening months in the job, explaining: "There won't be many of us. A lot of the guys go away, but those that remain will work and go again.
"We have had a tough period and there have been a lot of positives but also some negatives. Sometimes you have to accept the struggles you have.
"It is about regrouping and starting again. It is the second half of the season and there is a long way to go."