With Paolo Di Canio suspended it is an enforced change, and, although Glenn reiterates that it is right to use Jermain relatively sparingly at this stage in his career, he says: "I'm looking forward to the two lads playing together; it certainly has got a lot of potential and we are all looking forward to the game.
"It is always nice to welcome Liverpool to Upton Park and quite often you get an entertaining game."
Glenn insists the pair will be no strangers to each other's game against Liverpool and adds: "When Fredi has been fit we have possession games, small sided games, pattern of play work, etc, so they have worked together before.
"It has got a lot of potential and Fredi is key in our striking partnerships because he gives us that striking presence. Fredi and Paolo has proved to be an excellent partnership, now it will be interesting to see how this one goes.
"Jermain is still physically developing and he has a long career ahead of him so it is better to be patient with him; there is a temptation not to be but it often backfires on you.
"Young players often burst upon the scene but then pick up nasty injuries and you don't have to look further than Michael Owen who was struggling for almost a year with his hamstring before he really got back to full fitness again."
Glenn has reached the halfway stage of his first season in charge of the Hammers, and Liverpool were, of course, the first team he faced in charge this season.
"Time seems to fly by," he says, "we enjoyed the first game up at Anfield and we felt we performed well overall and deserved a point.
"It was a decent performance; as the away team we had to play on the back foot but with two banks of four we looked solid and we took some encouragement from the match.
"But in two separate incidences Michael Owen unlocked us and we ended losing 2-1. We have to be aware of Michael tomorrow - as well as the other 10."
Owen is of course looking for his 100th Liverpool goal and Glenn says: "He is such a young player and that shows how prolific he is."
But there are other dangers up front as well and Glenn warns: "When they bring a new player into the club it seems that it's not in ones but in twos, and on the same day they brought Anelka in they introduced Baros as well. At this moment people won't know too much about him but he is the golden boy of Czech soccer and they have secured the services of an excellent young player.
"There is nothing for Nicolas Anelka to prove, we all know he is quality. He is a world champion and he will be a major threat to all Premiership teams."
As for that half time report, he says: "There have been great moments of joy, and equally some times of utter despair, but the job has been more or less what I expected - with one exception, which is the amount of time you spend on the telephone talking to agents.
"The reason is that clubs these days never know quite how long they can keep their squads together, and you always have to be planning for eventualities.
"I would like to think, for example, that I had six or so players that would stay here for five years and allow me to build a squad around but the reality is that I am probably living in fantasyland.
"There have been a lot of emotions since I started the job I am so proud to do but obviously the lowest point was that 7-1 defeat at Blackburn - something like that should not happen in football and it was an embarrassment for everyone concerned.
"The highest point of the season so far is not difficult, though - far more experienced managers than me have been going to Old Trafford for years and coming away again with little more than a handshake, so to go up there and win deservedly means it is a game that I will remember for a long time."
Meanwhile Glenn is hoping that none of his players catch a virus as he looks to keep his senior players going for the second half of the season.
He has been under the weather himself this week and he says: "I'm just full of the cold but I haven't got the flu or anything like that. I'm conscious of keeping the players wrapped up nice and warm, and them not hanging around after training when they are still sweaty, but getting a shower straight away.
"It is critical we keep them physically fit in terms of not picking up injuries but also keeping them healthy as well, so they don't have the sniffles, or the cold or the flu.
"There are so many things to think about when you are operating with such a small squad."