However, Pastorello has suggested that the Belgian's career could have taken a different path, particularly had he won Serie A in his first season in Italy.
In an interview with The Telegraph, Pastorello said: "I think I can say without disappointing anybody that Manchester City came in the year before.
"During the pandemic, it was very complicated because of trying to fly to places to meet people. It started very concrete and very serious, but eventually they changed their idea or they were not ready to make it happen.
"Honestly, it was very difficult after the first year - it was almost impossible. He hadn't won the league with Inter and he wanted to do that, and it would have been really impossible. Then they focused on Harry Kane this summer."
Lukaku netted 24 goals during the following campaign as Inter won the Serie A title for the first time since 2009-10.