Responding to a newspaper story that claims he will sign for the current Premiership champions by the weekend - a report that also said Paolo was not a genuine injury concern for the trip to Elland Road - Glenn stresses: "I have been told about the article and the issue of was he injured or was he not injured for the Leeds game is a very important one.
"In a nutshell he WAS injured - he has got a tight hamstring that we could not risk against Leeds in case he damaged it to an extent where he would be out for a month.
"We are not in a position, with the size of the squad, to be able to take a chance with one of our senior players - one of our best players - where we can risk him breaking down during a game because there is no one of sufficient quality to replace him.
"So the policy has to be one of caution and patience. I'd have loved Paolo to have been fit to play against Leeds, and I'm sure Paolo himself would have loved to have played because it is a fantastic stadium, and it is a great stage to play on - especially as it was a live TV game.
"But the fact of the matter is that after we played Derby he went to see our physio John Green the next day and told him of a real tightness in his right hamstring that was so sore if he was to extend himself he would tear it.
"He came to see me personally and explain that, so John Green and myself were very clear after the Derby game that it was very unlikely that he would recover in time for Leeds - and he was obviously always going to be out of the Liverpool game because he was suspended.
"But it is very wrong of the newspaper to suggest that he pulled out of the game when he wasn't injured. I am saying he was, and we have got the medical proof.
"Every time a player is injured John logs that, and it is in his record book that he has got a hamstring that is causing him sufficient pain to stop him playing for the next 10-14 days.
"And by being cautious and patient that means for the game against Leicester he is going to be fine."
Glenn rejects innuendo suggesting that Paolo shies away from away games and adds: "If he is injured he is injured; he certainly didn't miss the game at Anfield this year where he scored a penalty, thankfully he didn't miss the game at Old Trafford where he created the winning goal, and he has been to a number of away games this year.
"He played in that very tough game against Leicester, which was never going to be a pretty game, and scored a very important goal, so he has played plenty of away games this year for me and I have no doubt that since I have been working with Paolo this year, when he has been unfit, he has been unfit, and there is nothing that he or anyone else can do about it."
Glenn emphasises that he is an integral part of his plans, adding: "As soon as he has regained his fitness he has come back into the team, and whatever people say about him, the one thing they can't say that he is not a very correct and professional person who prepares properly.
"It was not right that we should risk him and lose him for 4-6 weeks particularly since we are operating with such a tiny, tiny squad.
"I would prefer him to tell us and miss one game, rather than miss five or six."
As for the transfer speculation, he insists: "We are not in contact with Manchester United and the papers are having a field day at the moment running the speculation.
"We feel that it is unsettling for everybody, not only for the player, but the club.
"The speculation is obviously coming from somewhere but it is not coming from our end.
"I have a very good relationship with Paolo but have not felt it necessary to speak to him about it, nor has he spoken to me on the matter.
"He is concentrating on rehabilitating his hamstring, but unfortunately hasn't been able to come in today because our doctor has been round to see him and he is carrying a very heavy cold."
MD Paul Aldridge adds: "Despite the speculation there has been no contact with Manchester United about Paolo Di Canio and he was never going to play against Leeds once Glenn learned about the injury."
Paolo is not the only fitness concern at the moment, and Glenn adds: "The players are under strict instructions that with any niggle or problem whatsoever, immediately after any game, or certainly the next day, to tell us about it.
"We were very aware of the problem Michael Carrick might have with his knee because he told John Green immediately after the game, he treated it with ice, and, sure enough, the next day it was sore.
"He had made a terrific block on Patrick Berger but it just opened the knee joint up and we knew he wasn't going to be fit for the Leeds game.
"We did well to keep that quiet but, because the training ground now is a much more private environment, when these things happen we seem to be able to keep it to ourselves - which is very important.
"David O' Leary had no idea whatsoever that Michael Carrick or Paolo Di Canio were injured - in the past everyone knew our business."