The Reds have won only one of their last six games in all competitions - an FA Cup third-round replay against fourth-tier Plymouth Argyle - hampering their chase of Chelsea in the Premier League and leaving them with a 1-0 deficit to Southampton in the EFL Cup semi-finals.
Defensive lapses were to blame for Swansea's first and third goals at Anfield on Saturday, while Joel Matip has been a sore loss to the Reds as the farcical situation over his international retirement was allowed to drag on by FIFA.
James Milner has had to fill in at left-back this season, while Klopp has given both Loris Karius and Simon Mignolet time as first-choice goalkeeper as he struggles to find the right formula at the back to complement the Premier League's most potent attack.
But the manager feels that a forward line shorn of the Africa Cup of Nations-bound Sadio Mane and the injured Philippe Coutinho as well as a poor team approach to defending is to blame.
"We missed Sadio... we missed Phil for a time... we missed Joel Matip," Klopp told reporters ahead of Wednesday's second leg against the Saints.
"As much as I like Sadio, it's not that we had problems because we missed Sadio. We made other mistakes, not because we're not scoring enough goals. We scored enough goals to win the games.
"You always speak about defence, or players. I speak about the whole defence of the team. If it was to buy one player and fix it, I'd be silly not to do it but it's not that simple.
"I knew about the problems we had after Christmas and that was disappointing. I saw before the game [against Swansea] that we are back on the right track and we could see the freshness coming back in training.
"But then we have this game and it's not so nice. But that's part of life too.
"We had a long meeting after the game so I'm ready for the rest of the season. We've come through a very intense period."