Salah opened the scoring in last week's rousing 3-0 success at Anfield, before departing the action early in the second period with a groin injury.
That problem kept him out of Saturday's 0-0 draw at Everton, but Klopp was optimistic when quizzed on the fitness of a man who has scored 38 goals across all competitions this season.
"We're not sure 100 per cent, he was with the athletic coach yesterday," Klopp told a media conference ahead of Tuesday's return leg at the Etihad Stadium.
"Rather yes than no, but we have to wait and see for the reaction."
Before facing the media, Klopp also provided an update on Andrew Robertson and Alberto Moreno, both of whom missed the Merseyside derby with minor knocks.
"No real clue in the moment because we have to wait a little bit," he told the club's official website.
"You can imagine, in this short period between games, it is quite difficult, so I have to wait each minute I can and that's what I'll do. There's nothing new in the moment, we will see.
"With Mo, Robbo and Alberto, we have to wait a little bit, but of course [we have] big hope they will be back."
There was less good news regarding Emre Can, however. The Germany midfielder sustained a back injury last month and has been out of action since.
"That is not in the best place," Klopp added. "[He is receiving] treatment and we're still hoping it will be a little bit quicker than maybe we thought in the first moment. But we cannot say anything else."