The England international has not played a minute of competitive football since suffering a hamstring injury in the Reds' 2-0 triumph over Aston Villa before the international break, which meant that he had to withdraw from the Three Lions squad.
Alexander-Arnold failed to make the cut against Southampton in Liverpool's first game back, but he avoided a serious problem and was among the substitutes for Wednesday's Champions League battle with Real Madrid.
The 26-year-old failed to make it onto the pitch in that 2-0 victory, though, as even when his deputy Conor Bradley was taken off with his own injury late on, Slot selected Joe Gomez to see out the dying embers.
However, when asked in Thursday's pre-game press conference if Alexander-Arnold would be able to return to the starting lineup against the champions, Slot replied: "Yes, he would."
Alexander-Arnold fit to start, as Bradley, Konate updates provided
Alexander-Arnold's return to full fitness is particularly timely after Bradley was taken off with what appeared to be a hamstring issue against Real Madrid, where he put in a valiant display to keep Kylian Mbappe quiet.
Bradley was one of two new concerns for the Reds on the evening, as fellow defender Ibrahima Konate stayed down after the full-time whistle and had to be attended to by medical staff before gingerly making his way off the pitch.
Slot was in the dark about how serious Konate and Bradley's problems were on Wednesday evening and was similarly none the wiser on Thursday, although he conceded that the former's inability to take part in the post-match lap of honour was worrying.
"They are still being assessed so it's difficult to say where they are in terms of the injuries," Slot added. "Let's wait and see but it is never a good sign if players... Conor, I had to take him off and Ibou didn't walk off the pitch as he should have after such a fantastic game that he played.
"He should have made a round [of the pitch] and clapped the fans but unfortunately he couldn't so that's not a good sign. They are still being assessed and it is so close after the game yesterday night, and I just came off the training pitch. So, I can't tell you exactly where they are, so we have to wait and see where they are this weekend and after that."
Gomez or Quansah to replace Konate against Man City?
There is still a slim chance that Konate will make a miraculous recovery in time to face Man City this weekend, but given how awkwardly the Frenchman was moving on Wednesday, the signs are not positive.
Slot could therefore be left with an intriguing dilemma at the back for the visit of the champions, as Gomez and Jarell Quansah are set to go head-to-head for the chance to partner Virgil van Dijk if their superior is missing.
Gomez is undoubtedly more experienced in crunch clashes such as Sunday's, but his only starts this season have come in the EFL Cup, and he has racked up just 55 Premier League minutes from three substitute appearances.
However, Quansah has not played one minute of top-flight football since the opening weekend, and it was Gomez who was chosen to replace Konate at half time of the 2-1 win over Brighton & Hove Albion earlier this month.
The 27-year-old is seemingly first in line for a start if Konate is indeed unavailable, while Diogo Jota, Federico Chiesa and Alisson Becker are also expected to sit out the visit of the champions, who are eight points behind Liverpool in the Premier League table.