Osvaldo has moved to St Mary's on a four-year contract from Roma for a club-record fee of around £15million to hook up once more with Pochettino, who was his mentor at Espanyol three seasons ago.
"I've worked with Mauricio before and I know him quite well," Osvaldo said.
"The season I shared with him at Espanyol was my best season as a football in a personal and collective sense.
"It's fantastic to work with Mauricio. He's a great motivator and for me it's very important to work with people who appreciate and respect how I work.
"For some years, I've been working with people who don't appreciate how I work as a player, so it's great for me to to be working with people who do appreciate it."
The 27-year-old Italy international claims his long-held desire to play in the English Premier League was another reason for making his move.
Osvaldo added: "I've been dreaming about playing in the Premier League and I want to do something important in this league, so I've made this dream come true.
"I've always been a massive fan of the Premier League. The technical level of the league is amazing and it is very dynamic. Overall I'm thrilled to be here."