"I don't think anything is going to happen now," he says, "and that is why it is key that we keep everyone fit because after Thursday at 5pm no clubs can have any comings or goings.
"It would have been nice to be able to get at least one body in before the end of the season, even though there are only eight games to go - but it wasn't to be.
"We definitely targeted a couple of players but for one reason and another I wasn't able to make it happen.
"I am pretty frustrated that we couldn't get one loan player in but there we are - we have got to get on with the squad that overall has served us well, and we have got to continue working hard and playing hard to get as many points as we can in the final eight games."
Glenn looked at three trialists in a friendly game behind closed doors on Thursday against QPR - Trinidad and Tobago internationals Brent Rahim and Nigel Pierre, and Morroccan international Yassine Abdellaoui, but declined the temptation to take that interest any further.
"We looked at them. They did well and they didn't let themselves down, but we decided they didn't quite have the quality that we were looking for," he says.
"There is little point adding to the squad with players that you don't feel have enough quality."
Neither are any sales likely ahead of Thursday, though of course Glenn's one 'major' sale to date, Svetoslav Todorov, made a quiet debut, according to reports, for Portsmouth in their 0-0 draw with Sheffield Wednesday on Saturday.
Says Glenn: "Todorov, as a person, I liked greatly. He is a very nice man and he needed to play first team football at his age, he didn't need to carry on playing in the reserves.
"He will now be working for the man who signed him as Harry Redknapp has taken over at Portsmouth - with Toddy working with Harry again I'm sure that is going to help him."