The Croatian centre-back completed a £20m move to the Merseyside outfit last week, but he has said that he will not be fazed by making his competitive Reds debut against his former side.
"I won't think about Southampton, I will concentrate on my game and on my style," Lovren told Sky Sports.
"Maybe it was a difficult relationship at the end [with Southampton], but I said from the first day I wanted to come to Liverpool.
"I told them I want to leave because Liverpool is a massive club and maybe I will have this chance just one time in my life, so I don't want to stay and see the chance going.
"There is a lot of talent here, amazing players and last season they showed already they can do something. Now, with eight new players, I'm really confident in this team."