The Saints, having cemented their Premier League standing, were in a position to spend big during the recent transfer window.
They did just that in bringing the likes of Lovren, Victor Wanyama and Pablo Osvaldo to St Mary's.
Lovren cost £8.5million from Lyon, making him the most costly defender in the club's history, but he has settled quickly in England and netted his first goal in a 1-0 victory over Liverpool on Saturday.
On the Croatian centre-half and his fellow new boys, Pochettino said: "We are very pleased with his goal.
"When we were following him and we were about to sign him, we knew of his quality and we knew it would be easy for him to adapt and establish himself within the league.
"We already knew about his skill and his quality but the three signings that we made, Wanyama and Osvaldo as well, have all settled really well and really quickly so we are very pleased with the three signings."
Artur Boruc is another to have shone for the Saints over the early weeks of the season, with the Pole putting in an eye-catching display at Anfield.
Pochettino added: "He was great, outstanding. But it was not just him, the rest of the squad was outstanding.
"It's not easy to come here and win so to actually do that makes us really pleased.
"I think all the players need to be congratulated because they put in a great performance."