Ogbonna is to undergo surgery after sustaining the knee issue in the 3-2 Premier League win at the London Stadium on November 7.
Asked about the 33-year-old Italian at a press conference ahead of Saturday’s trip to Wolves, Hammers boss Moyes said: “He is going to have surgery, we think surgery will take place over the next couple of days.
“I think most people who know much about injuries and listen to what the doctors say, cruciate ligament injuries tend to take I think somewhere around about nine months.
“I don’t think there’s a quick return from cruciates. I think there is a period which has to be taken and recovery time. So I would probably say yes, I think it will be hard for Angelo to be back this season.
“It’s really sad, because he’s done a great job for us, he is a great boy, a great team player. He’s someone we love having around, and more importantly, his performances have been excellent. So it’s a real sad moment for him and also for us.”
It appears midfielder Declan Rice who withdrew from the England squad last week because of illness, is set to be available for the Wolves match.
Moyes said of his players who went away on international duty that “everybody looks OK”, before adding: “I may be wrong, but I maybe wonder how many people this week (at other clubs) won’t be fit.
“I just think it’s just beginning to take its toll on a lot of players, the amount of games we’ve had, especially the international boys. It’s quite quickly brushed under the table because people don’t like to talk about it. I just have a feeling you might find there’s quite a lot of international players who are toiling.
“I’m looking at England, the players who had to drop out. Declan Rice had a terrible virus, played against Liverpool brilliantly well, but was incredibly ill. We can see things are happening. It’s just part of football, whether it be illness, injury, or whether it just be general fatigue for them all.”
Moyes was also asked about Glenn Hoddle describing Rice as “the best player in the Premier League”, and said: “He’s a really good judge of player, so if you’re getting that from Glenn Hoddle, it will not be far off the mark. At the moment he’s as good as any in my mind.”
The Liverpool result, West Ham’s fourth successive league win, saw Moyes’ men replace the Reds in third place in the table, going three points behind leaders Chelsea.
The Scot, who guided West Ham to sixth last term, said his side are not title challengers, adding: “I want to challenge the top four. I don’t see any reason why I don’t want to try to take it on and have a go at it.
“I genuinely feel as if we can play better. I think there’s more to come, we’ve got players who can step up again and I’m expecting that from them in the coming weeks.”
Moyes also spoke about Czech businessman Daniel Kretinsky, Sparta Prague’s owner, completing a purchase of a 27 per cent stake in West Ham last week.
“I got a chance to meet Daniel after the game against Liverpool,” Moyes said.
“He seems a very charming fella, and I think he’s a really good addition to the board, everybody is telling me, so I look forward to working with him. I’ve only had a five-minute conversation with him.
“It looks and feels like a good move for West Ham, and I think not only the club but supporters feel that way. I think we’re all looking forward to him having an impact and helping us going forward.”
West Ham are set to play their Europa League match at Rapid Vienna next Thursday behind closed doors after Austria imposed a lockdown, with UEFA confirming on Friday the match is planned to take place as scheduled.
The Hammers this week were banned from selling tickets for the game following crowd trouble when they played Genk on November 4, and that sanction is not being transferred, with UEFA saying West Ham still have to serve the suspension against Rapid regardless of any decision taken over home spectators.
UEFA said in a statement it was “closely monitoring the situation and in regular contact with the Austrian Football Association and SK Rapid Wien, who are in turn liaising with the relevant competent authorities” ahead of the match.