The 27-year-old forward made his move to St Mary's from Italian side Roma having spent most of his career in Serie A.
"I am getting adapted to English football. It is very different to Italian and Spanish," said Osvaldo in an interview with Telenoche.
"In England, football is much more physical than Italian and Spanish, and it is played with an impressive rhythm despite the fact it's less technical than in Spain.
"What I like very much is the passion of the supporters, it's like they are crazy during the match but once it ends, everything is calm. They salute their team and go home without any problem, that's fantastic."
Osvaldo will be looking to impress Saints boss Mauricio Pochettino when they face Swansea City on Sunday.