The forward was carried from the pitch in stoppage-time of the 1-0 win at Anfield and will subsequently miss Liverpool’s remaining eight fixtures prior to the international break in November, as well as his country’s participation in the Qatar finals.
Jota does not require surgery on the issue, however.
Offering an update at his pre-West Ham United press conference, Jürgen Klopp confirmed: “It's really not good news about Diogo. Yes, he will miss the World Cup. [It's a] pretty serious injury in the calf muscle and now the recovery process starts. That’s it pretty much.
"That is the first diagnosis, which was pretty clear, and all the rest will now follow in the next few days.
"It is very sad news for the boy, and for us as well of course [and] for Portugal."
Klopp did not put a timescale on Jota’s return to action, adding: "[It will have a] big impact. So now we can say that because he will not be in for a long time; we talk about months.
“So, we will see. I don’t want to put now a number on it because I always hope in the middle of the rehab there is a very positive development and we can cut days off the rehab phase, but it will be long."
The injury is the second Jota has suffered in 2022-23 so far, with the No.20 missing the opening weeks of the campaign due to a hamstring complaint.
Asked how the 25-year-old had reacted to the news, Klopp said: “It’s Diogo and he’s surprisingly OK, so far. He is an incredibly smart boy and very reflective.
“I think he knew it when we carried him off the pitch, when I spoke to him for a second. When I came out, we passed each other after the game and he explained what happened. I think in that moment he knew already it was a serious one and could be pretty impactful for his World Cup dreams."