The Brazilian goalkeeper suffered a hamstring strain in the Premier League draw with Brighton at the weekend and was replaced by Caoimhin Kelleher in the 1-0 win over the Dutch side.
Reds boss Jurgen Klopp said he hopes to have Alisson back within a week but that a much more realistic timeframe is for him to return in 10-14 days.
‘He told us after the last game that he felt in the 60th, 70th minute his hamstring. [We] did a scan, it’s a little one but enough for today and probably for another week,’ Klopp told BT Sport on Tuesday night.
‘We don’t know exactly, we have to wait and I’ve never heard about a hamstring that is only four or five days, so 10-14 days I think.’
Alisson is certain to miss the Premier League clash with Wolves at Anfield on Sunday evening as a result.
The Reds go to Fulham in the Premier League on 13 December, which could see Alisson return, but Klopp may want to ensure that he is fully fit for Tottenham visiting Anfield on 16 December in a potentially crunch fixture in the title race.
22-year-old Irishman Kelleher was something of a surprise replacement for Adrian against Ajax, with Adrian left on the bench.
He impressed, though, and Klopp was delighted with him, so we can expect to see him start against Wolves this weekend.
‘Top. Top, top, top,’ Klopp said of Kelleher after the Ajax win.
‘It is a situation, which I have to say, it was easy to decide for Caoimhin because he just deserves it, but it was difficult to decide against Adrian because he did really well for us: a lot of clean sheets, what a season last year, Super Cup final and all these kind of things.
‘He did a really good job, but we needed the package of Caoimhin – and he is a top talent anyway, but a really good shot-stopper and a top footballer, so I like that.
‘We needed that for the pressing of Ajax, we needed his chips from him into the half-spaces and these kinds of things. That was really good, but of course in the end it is all about saving, keeping the ball out of the net, and he did that at least twice in an exceptional manner. I am pretty sure he will either sleep really well or not at all, but he will enjoy both.’