“I hope that Salah remembers the day we were together in Stamford Bridge dressing room after he'd had a poor performance," he told Qatar's Al Kass Sports Channel.
“I asked him to be patient and told him ‘You are a good player and you will become a great player'.
“Salah has turned into that big player and will write his own story through persistence and strong desire.
“The whole thing depends on Salah himself, he has unbelievable skills and is currently performing at a top level that's allowing him to compete for Ballon d’Or.”
Though's Salah has significantly improved since his spell at Stamford Bridge, he is enduring a lean start to the 2018-19 campaign.
He has netted seven goals in 16 appearances in all competitions but has failed to hit the heights of last season, with a succession of missed chances leading former Arsenal defender Martin Keown to conclude that Salah is out of sorts.
"I look at Salah, and he doesn't look the real deal for me," he told BT Sport.
"When you really look at him, he was really quiet today. Something is wrong.
"Maybe the injury he has is affecting him and he doesn't want to get hurt. He's not really the same player."