Southampton manager Ralph Hasenhüttl has said that his side's inability to match Newcastle United's intensity cost them in their 3-1 defeat to the Magpies on Saturday.
The Saints came into the game on the back of a 3-1 win against Wolverhampton Wanderers but put in a tepid first-half display against Newcastle, where Ayoze Pérez scored twice in the space of five minutes.
The visitors improved in the second half and pulled a goal back through Mario Lemina but Pérez completed his hat-trick late on to secure the three points for the home side.
Speaking after the game, Hasenhüttl admitted that his side's passive first-half display was not good enough.
As quoted by the club's official website, he said: "It was an intense game. First half we were not able to stop them. After 20 minutes, it seemed we got out of the pressure but then there was the situation with the corner and a counter-attack against us, where we made a foul.
"The crowd was loud and their team was very aggressive. We were sitting on the back foot and it was not good enough today.
"I have to say it, in the first-half it was too calm, too slow and not aggressive enough. In that way, you can't play in the Premier League because you have no chance.
"The opponent was very good today, very aggressive and physical. We had no chance to keep the ball and that creates pressure sometimes."
The 51-year-old brought on Mario Lemina and Stuart Armstrong at half-time as well as changing Southampton's formation from playing with a back five to a back four. While this led to a goal and a better performance in the second half, Hasenhüttl claimed that the Saints' first-half performance had left them with too much to do in the second.
"In the second-half we were coming back from 2-0 down but against such a team in this stadium it is not easy to come back.
"We tried everything and had a few chances for an equaliser. We played very well in the second-half but it was too late."
The defeat leaves Southampton in 16th place, five points clear of the relegation zone with four games remaining.
The Saints will look to strengthen their Premier League status when they play FA Cup finalists Watford on Tuesday before facing Bournemouth in a south coast clash at St Mary's next Saturday.