The Blues initially sent the Egypt international on loan to Fiorentina just 13 games into his Stamford Bridge career, before eventually selling him to Roma in 2016.
Salah returned to the Premier League with Liverpool at the start of the season and recently admitted that he is pleased to have proved his former side wrong, having netted 31 goals in 33 top-flight outings.
Conte understands why his side did not fight to keep the 25-year-old on their books, however, telling reporters: "It's not so simple. We have to compare Salah of four or five years ago, and not this Salah now.
"Salah in the present has improved a lot, developed a lot his football. The experience in Italy was very important for him. Now I'm sure that he's a different player compared to in the past. For this reason, this comparison is very difficult with the players."