Jermain got off the mark at Peterborough with a stinging shot that compensated for the frustration he felt in our first pre-season outing - when he failed to convert a number of chances at Bishop's Stortford.
Glenn says: "The important thing is that Jermain Defoe was there to miss them on Friday night and the fact that the goals didn't go in that night didn't concern me.
"But against Peterborough, he scored a great goal, something we will hope he will do many more times for us in his career.
"He is such a bright player and makes terrific runs, and his movement is excellent.
"He is always asking defenders questions and as a result he is continually making chances.
"I am sure he will get goals next season whether in the first team or the reserves.
"I think we mustn't hype him up too much because of what he achieved last season at Bournemouth.
"He will, I am sure, be involved in the first team in some shape or form, and whatever he does will be a bonus for us.
"I'm sure the season after is going to be his time - he is certainly a prospect for us and we are very, very hopeful that Jermain Defoe is going to be a top drawer striker.
"He was upset about missing the goals at Stortford but he gets on with it very quickly and, typical of a terrific striker, he goes in there with a belief that if he misses he is going to score next time.
"He has the perfect mentality for a top class striker and with all the different techniques he has got in his locker for being able to put the ball in the back of the net, it is just a question of him being patient.
"And we mustn't put him under too much pressure where the expectations are too high too soon.
"If you do that you can put a young player's progress back a long way.
"I've seen too many young players broken because they have been brought in too soon, especially if they come in and lose confidence because of the physical aspect.
"Jermain Defoe's time is really from next year onwards - I wish he was a year older but we are going to have to be patient."
Glenn insists that he will not be farmed out on loan this campaign - despite a clutch of clubs desperate to borrow his goalscoring skills.
"He is not going on loan this year, we will keep him around, and don't be shocked if he plays a few more games by the end of the season than people thought he would do," he says.
"If anyone does ring up to see if they can take him on loan this year it will be a waste of a 10p phone call."
On the win at Peterborough, Glenn adds: "Overall we were very pleased with the workout because those games are never easy.
"You only have to look at Sunderland losing at Mansfield to see that.
"I thought the boys attacked in the right manner and that Peterborough made things as difficult as they could for us.
"Now we are looking forward to our trip to Stevenage next Monday."
And rather than pick out individuals from the Posh game, he gives a glimpse of his philosophy for the coming season.
"It's a team game and we are very much focused on that this season," he says.
"It was an absolute team performance at Peterborough and I wouldn't want to single anyone out."