Salah has re-joined the Liverpool squad after representing Egypt at the Africa Cup of Nations, a tournament which saw the winger leave for Morocco amid a degree of controversy.
Prior to his departure, Salah had publicly criticised both the club and Slot, comments which prompted widespread discussion among supporters and pundits.
However, speaking ahead of Liverpool's upcoming Champions League fixture against Marseille on Wednesday night, Slot struck a conciliatory tone when asked about the situation.
"I am really happy and pleased he is back," Slot told BBC Sport.
"In his absence, I think we have done quite OK in terms of hardly conceding any chances and starting to create more and more.
"If you create more and more, then it is really helpful to have Mohamed Salah.
"There has only been one who scored more for this club [who is alive] but I don't think I can play Ian Rush still! Then it is really helpful to have him back."
He added: "I spoke to him today, and I'm happy to have him back because this season I've only had two wingers who've played more than 100 minutes in the Premier League and that's Mo and Cody [Gakpo].
"Jeremie Frimpong and Florian Wirtz can also play in these positions, but if I asked Florian what was his favourite position he wouldn't say left or right wing. Jeremie would be the same, but he's shown what he can do off the right side.
"I saw today that Mo has 45 goals for Liverpool in the Champions League and the next highest is Virgil van Dijk with five. So it is nice to have him back, especially if he is able to reach those levels that brought him 45 goals again."
