He praises them for keeping the Hammers' tight squad up and running, and is delighted that - touch wood - the injuries appear to be clearing up.
Ian Pearce is continuing his rehabilitation and getting closer to a comeback, while Steve Bywater is just a couple of weeks away from full training after breaking a bone in his wrist.
With Izzie Iriekpen playing at Stevenage Borough on Tuesday night, and hoping to put three years of injury misery behind him, the list of injured - bumps and bruises notwithstanding - is shorter than it has been for many years.
Steve Lomas made a quick recovery from his toe injury to come on as sub at Chelsea on Saturday earlier than had been at first hoped - a testament to how fast the staff at Chadwell Heath are getting players back to business.
Says Glenn: "I am really impressed with John Green and his medical team, and obviously I include John McCarthy in that, as well as Russell Holman, who has taken on a dual role this year as John McCarthy's assistant, if you want, in the fitness department, and as a masseur on match days.
"I am really pleased with the whole backroom team. They have worked really hard so far and they sometimes don't get a mention - in my eyes they are unsung heroes."
Nonetheless, Glenn insists risks will not be taken with players' fitness - even if there is a temptation to do otherwise.
"By nature and learning by experience I am a great believer that, although it is uncomfortable at the immediate time, patience will pay off in the long run," he says.
"I'd like to think I have never put a player into the fray unless we were all 100 % convinced that he was going to get through the game without any problem.
"There is not one player this year that I have thought, before putting him in, that it was a big gamble, and most times that philosophy does pay off.
"Very occasionally you think they are fit and for whatever reason they don't get through a game. We had a problem earlier in the season with Fredi at Derby when we put him in and he lasted about 65 minutes before he had to come off.
"That held him up for another couple of weeks but I do believe that a cautious approach does pay dividends in the long term.
"But with hardly any strength in depth whatsoever it is uncomfortable at times."
Glenn would like to get the sort of quality of Jermain Defoe in all positions on the subs' bench, so he has real options in all areas of the field, and he adds: "We are very fortunate at the moment to have young Jermain Defoe to come on.
"If you had that calibre of player in all departments that is when you would be saying 'we have now got some strength in depth' - but we are a long way off that at the moment.
"But it is something we are working towards over the next few seasons - that we get a squad situation we are all happy with."