He has been working hard with the players to prevent a repetition of the Newcastle game when, in his words, three of the four goals were unacceptable.
"We have been working every day as it was not appropriate to have a day off," he says.
"The players will not have got to bed until two or three o' clock on Tuesday morning but were back in on for training later that morning.
"We have had a good look at the video of the game and highlighted some very important points; I think the video is a good tool.
"We had a game plan where were going to stop them creating chances and we did that for an hour - but the first goal was the killer goal.
"We lost our concentration at a set play and when that happens you get punished at this level - you rarely escape.
"Thereafter we didn't take the game enough to Newcastle before we conceded the second goal and the third and fourth were shockers, really poor defending which was not acceptable.
"I don't want this to become a theme, that every time we have got to defend a wide free kick or a corner we freeze and don't do the job properly.
"It is totally in our hands, we have to solve the problem, and we have the players who are capable of that."
With Arsenal chasing a 15th Premiership win on the trot, the task couldn't be harder, and Glenn adds:
"All the teams that didn't pick up a point at the weekend will take the same view as us, that it was a poor start to the season.
"Arsenal got off to a good start by beating Birmingham; it was only 2-0 but I think some of these big teams now get the game won then control it to such an extent that there is no way back.
"I was at the game and they proved to me they are every bit as good as last year and it is going to be very hard for Manchester United or Liverpool to wrestle the championship off them."
With Fredi Kanoute back Joe Cole will revert to midfield - but he escapes criticism for Monday night.
"I think Joe was one of our few successes on Monday; he was full of running, never shirked his responsibilities and showed lots of energy to cover the ground for 90 minutes.
"We know he will be more effective coming from midfield which is a more natural position for him.
"I thought Defoe worked hard but we never got the sort of quality service in to him that he needs; he must have the ball to his feet, but we didn't do that in the way Newcastle got the ball to Shearer's and Lua Lua's feet."
Fredi's return may mean Eduoard Cisse dropping to the bench, as he continues to build up his fitness.
"We knew Eduoard Cisse wouldn't get through 90 minutes on Monday," says Glenn.
"He has got a lot to offer, but we got him two weeks too late to have him fully fit for the game, but with Steve Lomas and Don Hutchison being injured it was a case of being completely stretched in midfield."