Mohamed Salah has scored 43 goals for Liverpool this season
Salah, who has scored 43 goals for Liverpool during an astonishing season, tormented Chelsea while playing for Swiss side Basel and moved to Stamford Bridge in January 2014.
Limited opportunities saw the Egypt forward join Fiorentina on loan a year later and then Roma on a temporary deal that became permanent.
Mourinho, now at Manchester United but previously the manager of Chelsea, has been criticised for not keeping the 25-year-old at the club.
“It’s not so simple,” said Chelsea boss Conte. “We have to compare Salah of four, five years ago, and not with this Salah now.
“Salah in the present has improved a lot, he has developed his football a lot. I think the Italy experience was very important for him and now I’m sure that he’s a different player, compared to the past. For this reason I think it’s very difficult to have this comparison.”
Mourinho said Salah was not playing much for Chelsea and the club decided to send the player out on loan when he was in charge.
“He went to Fiorentina, after that I left and I am not responsible for the process,” he said. “Credit to him, Jurgen (Klopp), the team and I am very, very, very happy for him, that’s why we keep a good relation.
“He is a fantastic boy and he knows I have a great care for him and I’m really happy for the things that are happening for him. He more than deserved his player of the year (award).”
With four games to go in the Premier League season, beginning at Swansea on Saturday, Chelsea are fifth, five points behind fourth-placed Tottenham, who play Watford on Monday.
Asked if it was realistic for Chelsea, who play Manchester United in next month’s FA Cup final, to overhaul Spurs and clinch Champions League qualification, Conte puffed out his cheeks.
“Realistic? As you know very well it won’t be easy, but at the same time we must try,” said the Italian.
“The only way to put a bit of pressure on Tottenham is to try to get three points tomorrow. Otherwise it will be very difficult to put pressure on Tottenham.”
Conte said Brazil defender David Luiz, who has not played since February, could return before the end of the season.
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