Jurgen Klopp put Liverpool's recent dip down to defensive issues after their FA Cup run came to an end at Chelsea on Tuesday.
The Reds went down 2-0 at Stamford Bridge, an error from Adrian – standing in for first-choice goalkeeper Alisson – allowing Willian to open the scoring before Ross Barkley added a second after the break.
Liverpool had also lost 3-0 at Watford on Saturday, their first reverse in the Premier League this season, and have now conceded two or more goals in three consecutive matches for the first time since 2016.
Joe Gomez's return to the starting XI next to Virgil van Dijk failed to shore things up at the back against Chelsea, though Klopp is not too concerned by a run of just one win in four outings.
"Look, it went our way for so long because we defended outstandingly," he said.
"Usually you don't get a lot of chances against us and stuff like this, but now we have to admit that in the last three games – [maybe] four – we have conceded absolutely too many goals, that's true.
"I am not worried about the momentum – momentum is not something you get as a present, you have to get it to keep it. We have always a chance to get it back.
"I am not concerned about the momentum, but it is football and we never thought it would be an easy season, it would be an easy period, it would be an easy game tonight. Nothing, it was always clear it would be difficult – it was always clear it was difficult.
"We did very well, but tonight not good enough in decisive moments and that's what we have to accept."
Kepa Arrizabalaga made a triple save to deny Sadio Mane, Divock Origi and Curtis Jones in quick succession when Chelsea only led 1-0, though Liverpool failed to muster an on-target attempt in the second half.
Still, Klopp was pleased enough with the display, particularly after he had rotated his squad by making seven changes to the starting line-up.
"The performance tonight was completely different at Watford," the German said. "Against Watford it was really bad, tonight it was not bad.
"It was a really super-intense game. We made seven changes and we knew it would be intense and that's why we made the changes because it was clear a lot of sprints, spaces in midfield.
"How Chelsea plays, how we want to play, it was clear you need accelerations constantly. They offer that constantly and that's why we had to make the changes, or we thought we have to make them.
"That performance tonight, I am not concerned about [it]. That's football, if you make decisive mistakes then you lose football games."