The 22-year-old says he consulted his Netherlands team-mates and former head coach Louis van Gaal before deciding to snub interest from others in favour of Serie A
The 22-year-old sealed an €8.5 million [£6.7m] move to the Italian capital from Feyenoord this week after playing a starring role in Oranje's run to the World Cup semi-finals.
The young centre-back explained how he consulted Strootman of Roma and AC Milan's De Jong, with Louis van Gaal approving the switch, before finally settling on the move to Serie A.
"A lot of people [gave me advice] as this is a crucial moment in my career," he told AD. "Strootman and De Jong gave me a good picture of Serie A but [ex-Feyenoord striker] Graziano Pelle was also very positive.
"Also Louis van Gaal thought it was a good step. This was the right moment for me to go. And I feel this is the right club for me.
"When I heard from my management that Lazio were interested, I wanted to hear their plans. Also I felt this would be a good step for me.
"My meeting with Igli Tare, the sporting director, was very good. Lazio have clear plans and they told me my role in their plans.
"It became clear that Lazio wanted me very badly. Tactically I'm very strong but I could make a lot of progress with my defending. In Italy you can become a better defender, everybody knows that."
De Vrij was also a target for Manchester United, but is confident that he made the right choice in snubbing the Premier League for Serie A.
"That was on the basis of seven games at the World Cup. But Lazio were my No.1 from the first moment. I think Italian football suits me better at the moment."