Reports that he would be back in a fortnight - or indeed three months - have proven unfounded, and club doctor Ges Steinbergs, speaking just after the op, says:
"I am with him, he has just undergone an operation to repair the cartilage with an arthroscopy, and now he is recovering from that.
"It follows the injury on Monday night when he twisted his knee quite early on - that resulted in damage to his lateral cartilage, which is the more difficult one, more so than a medial cartilage.
"I have had a long chat with him and his spirits are up; no one likes to be injured, least of all Paolo, and thankfully in all his career he has not had that many injuries.
"The first thing he said when he came back from the anaesthetic was what was the score from Monday night, so he still cares; I said they were still playing and I would let him know!
"But, seriously, he is disappointed he is not going to be involved in the next few matches especially with big games like Manchester United coming up - and the busy Christmas period.
"He wants to be there and wants to contribute as much as he can, and it is frustrating for him to be on the sidelines.
"But, as we know with Paolo, whenever he is out for any length of time, he comes back like a piece of elastic, twice as fast and twice as fit.
"He is a true professional who works very, very hard and even comes in on his days off.
"He is already thinking about his regime of getting his upper body and his left peg even though most people would just rest up at home, watch the football, and read magazines when the surgeon said to him he can't put any weight through the right leg.
"He is going to be working hard from day one and as soon as he has recovered he is going to keep active and keep moving.
"He wants to come back and perform well for West Ham; he is determined to contribute as much as he can to this season, which has obviously been a difficult season.
"The time we expect him to be out is really eight weeks; obviously that is what we think at the moment, but it might be a week either side; the lateral ones are prone to problems and if it is a shorter time that depends on how the knee settles down.
"But, Paolo being Paolo, he is resting up today, and he is keen to get going - and I am sure he will be rehabbing on Monday although he won't be able to do much with the right knee to start with."
Ges also reveals that the state of Paolo's knee - the injury is notwithstanding - is and good, and says:
"The surgeon was absolutely pleased with the inside of his knee, saying that he has got the knee of a very, very young player.
"There was no other damage in the knee, and the surgeon couldn't believe that he had spent so many seasons in Serie A, the Premiership, and the Scottish league without injuring his knee so much.
"So it may well be he is of the opinion he will play until he is 50, or maybe longer and break Stanley Matthews' record of 52 - so maybe he needs a 12 year contract!
"But they are very pleased otherwise, we just have to let the injury settle down, and Paolo will be back into the fire as soon as he can, which he obviously wants to do."
Paolo played on through the pain barrier on Monday, despite getting the injury, caused by catching his studs in the turf, in the first half, and Ges adds:
"He was obviously in a lot of difficulty but when we looked at him at half time we suspected it might be a tear; Paolo played on with it until about 10 minutes from the end of the game.
"You could tell he was carrying an injury but he was determined to carry on playing his best for West Ham under what was very difficult circumstances.
"He went back onto the pitch because he didn't want to let anybody down - the team or the supporters - and he really did carry on playing with a injury that was painful.
"He chose to stay on when he could have come off - there is courage and determination for you.
"There was always a chance that he could have made it worse, it was a risk, and we put that to Paolo, but he decided that he wanted to carry on.
"Even with his injury he still looked a class player and it didn't make it any worse."
As for what the immediate future hold, he says:
"He will be able to work on his left knee and keep his body going but he can't put any weight on the knee for a couple of weeks.
"He wants to keep himself as fit as possible so he can return to West Ham and continue to battle out the season.
"Injuries are hard things for players to deal with; I think sometimes we just assume it is an easy thing to deal with, but it isn't.
"Players like Paolo just like to be playing every week, but suddenly he is faced with a break and rehabilitation."
Paolo has not long since come back from an injury which ruled him out from before the end of last season to after the start of this, and Ges adds:
"When he did the medial ligament in his left knee he was working solidly all the way through, he followed all the instructions, and he has not had a problem with it.
"We are hoping this will be exactly the same and that he will come back as fit as he was before."