Liverpool manager Jurgen Klopp revealed that he took off Dejan Lovren at half-time in the 3-2 defeat at Southampton because the centre-back had been booked.
The Croatian was replaced by Martin Skrtel, making his first appearance since December 20, and the substitute had a torrid second half as Southampton came back from 2-0 down.
Skrtel conceded a penalty and struggled with Mamadou Sakho to contain Saints forwards Graziano Pelle and Sadio Mane.
Asked why he substituted Lovren, who came close to conceding a penalty of his own just before the break, Klopp replied: “His yellow card.
“I thought at the end of the first half it looked like the ref was not completely free anymore of the emotion in the stadium.
“Maybe he thought later it was a penalty with Dejan Lovren, I don’t know. I thought, ‘we need to change this’.
“The first battle, the first challenge in the second half it was clear they would play a lot of long balls to Pelle.
“It’s not easy for a centre half [to challenge for these balls] coming out without a yellow card, especially when the ref changed a little bit the mood.”
Despite the change, Skrtel gave away a penalty within minutes of coming on.
“We lost formation in the second half and we couldn’t avoid these longs balls to Pelle,” said Klopp. “Always he’s fighting for second balls.
“If you’re not compact you have the problem that they are back in the game.
“When they scored their first goal it was clear something would happen in this game.
“[In the] Second half Southampton deserved the three points.”
Despite the disappointment of seeing his team throw away a two-goal lead, Klopp was philosophical after the match.
“I’m not angry, I’m frustrated because we got nothing for a very good first half.
“When you play a very good first half, then not that good second half, for me that sounds like a draw.”
According to Klopp, his players need to learn how to adjust their tactics in such situations.
“When you saw the situation where we had three players on the left wing and we played short passes, each short pass there was the next invitation for Southampton to win the ball back,” the German coach explained.
“When you are in a small space you have to come out, switch the side, and then they have to run, and they have to [try to get a] grab on the game.
“They are football mistakes. We have to learn and we will, but today it’s too late because we lost.”