Lukaku was linked with both the Old Lady and Inter Milan last summer but ended up sealing a £74m move to the Nerazzurri as the transfer window neared its closure in England on August 8.
Dybala on the other hand, was pursued by both the Red Devils and Tottenham Hotspurs but ended up staying at the Allianz Stadium as his wage demands reportedly served as a stumbling block to a deal being done.
Pastorello is of the opinion that Dybala’s failure to leave Turin did not free up space for Lukaku to join Juventus, but the former Chelsea striker was also swayed by the affection he was shown by Inter.
"If Lukaku is wearing the Inter shirt today, it's only because of Paulo Dybala's failure to join Manchester United," Pastorello told Sky Sports Italia.
"Romelu wanted to leave the Premier League and move to a club where he felt loved," Pastorello said.
"He immediately noticed the affection and warmth of the Inter fans compared to those of Juve, and this made the difference.
"Lukaku's arrival at Juve would have pleased many fans, but for Inter his engagement instead represented a turning point after the arrival of Antonio Conte, the intention to try to start a winning cycle.
Lukaku has been a revelation since moving to the San Siro, notching 23 goals in 35 appearances across all competitions.