The team have just negotiated a hectic festive schedule of four games in ten days and a few normally slick movements broke down in the second period against Rovers. Glenn explains that when tiredness creeps in the first thing to suffer is sharp passing.
"That was down to one thing - fatigue," said Glenn on a shortage of sustained possession. "When you are a passing team you take more out of yourself if you're making angles and running off the ball.
"That is the first thing that stops when you're fatigued - and we were very tired against Blackburn.
"Credit to Darren, Gus and Steffen, we've had a real hard workload there and they dug in for us. We came through a very difficult time in the game.
"It was a good day for us, a very good day for us for different reasons. We weren't at our very best and we picked up three points. This Christmas period we've had much better performances and not won so it's good to balance it out.
"I delighted, it keeps us in touch. We've got a big schedule ahead of us with the two cup games against Chelsea and the FA Cup. So we're not going to get that much rest over the coming period so we're going to have to get used to winning like this."
Glenn went on to reason that as his development plans evolve he will add to the squad as he builds to compete with teams who are much further down the track in terms of playing strength.
"We've got to be very aware of that and the squad does need need to be strengthened over the coming years.
"There has been a lot of good aspects to our play this season, but this shows you we've still got to improve."
Special mention was reserved for Darren Anderton, who put in another strong performance in the centre of midfield following that at Aston Villa.
"He was excellent at Villa Park, he was as good as I've seen him for a long time there. He's really been consistent for us.
"I think what you've got to realise, in the second half against Blackburn he was putting tackles in, he was tracking people - his work rate is there for everybody to see.
"He also has his creative side and if he keeps playing like that we've got to be pleased with that sort of input from a midfield player."
Glenn says that the fatigue-factor came into play during the second half against Blackburn.