The scheduled game against Fulham was, of course, called off due to their European commitments, and Glenn says:
"Losing the Fulham game was a real body blow for us because it was a Sky game and there is a lot of money involved on those.
"We are talking about hundreds of thousands of pounds, and it doesn't help our cause in terms of finding one more player before the window closes.
"And, like last year, we are going to be a game behind everyone else and we can't really see where we are going to fit the game in at the moment.
"There are not too many spare dates this side of Christmas what with internationals, European fixtures, Worthington cup games...it is not clear when we will be able to rearrange it for."
Glenn still hopes to overcome that blow by bringing a forward in, and he reveals:
"We are monitoring one or two particular players, and if we can go that extra distance we will try and get one in before the end of August, but I am not going to bring a player in just to make the numbers up.
"We have a list - quite a small one - of potential players that we could bring in before the 31st August, but whether we can make it happen, I don't know yet.
"We will just take our chance; I do think we have got some more strength in depth than we had last year, though you always want more."
If he doesn't get one in, Glenn admits he may have to rely on the adaptability of some of his players to fill in if needs be, and he says:
"We have got versatile players at the club, for example Trevor Sinclair, who, the few times he has played as a central striker he has been outstanding, particularly in the game against Sunderland.
"Him and Defoe looked a great partnership, and I know he can play through the middle really well, as can Don Hutchison who has done that many times for Scotland, and he can hold the ball up and bring others into play.
"But we lost Paul Kitson in the summer, and to have one more striker in the club would be good - then I think we would have to say that is the squad we have got to go to war with."
Despite the hardships, Glenn is remaining upbeat, and he adds:
"I am always optimistic; anyone who is a football manager has to be optimistic because pessimism doesn't get you anywhere.
"You always have to believe that the next day, what you are trying to do might actually happen.
"There is still the best part before the window closes, and if it is at all achievable, hopefully we will do it in the next three weeks.
"If not, we will have to take our chance and get through to the January window when the transfer market opens up again.
"We will just play it by ear - the important thing is not to make too many mistakes in the transfer market."