Schalke winger Michel Bastos is currently on loan from French outfit Olympique Lyonnais, where he played alongside newly-signed Southampton defender Lovren.
The pair remain close, and Croatian Dejan says he will be passing on some insider knowledge about his friend to his new teammates this evening.
"We are friends and always will be because we played together at Lyon for three years," he told Saints Player
"I spoke with him yesterday, and it will be funny to play against him tonight. He is on Luke [Shaw]'s side, so I will tell him everything about Bastos!
"We've played against two lower-division teams in Spain, and they are not at the level like Schalke's," continued Lovren, who made 45-minute appearances in Saints' wins over UE Llagostera and Palamós CF last week.
"I think we'll have a good game today. I think that's an important match to win."