Glen, who has featured in the first team squad this season - although he has yet to make it to the bench - is likely to feature regularly in travelling parties in the months to come as he integrates with the first team squad.
Glen is currently on duty with England U19s in Hungary.
There has been some debate throughout his development about whether his best position was there or at centre half, where previous manager Harry Redknapp - who saw West Ham 'live' for the first time since he left the club in the Spurs defeat on Sunday - described him at a post-Southampton press conference at the Dell once, though not naming him, as "the next Rio Ferdinand."
Now, it seems, his future has been settled, and the Hammers boss says:
"Glen looks like he could be a top drawer right full back in 18 months or so and I have high hopes for him and Anton Ferdinand."
The teenager is already way ahead of his age group and played for England U19s recently in Scandinavia.
"That U19 tournament in Norway did him the world of good," says Glenn.
"He came back in great condition and of course got on the pitch against Reading and Vitesse Arnhem in the friendly games this summer."
He made Titi Camara's goal in the reserves' firs win of the season over Wimbledon, and Glenn adds:
"He is physically strong enough for the reserves, and has come into the first team group now.
"There is lots of raw material to work with and Tony Carr has done a terrific job with him - but I have had to take him off Tony now!
"If Glen and Anton dedicate themselves they could go a long way in football, but they will, of course, have to work hard if they are to progress."
Glenn believes the policy if blooding youngsters will continue to pay off, and says:
"This is a club that gives youth the opportunity to play in the Premiership.
"I am a great believer that if you give trust to players that trust is repaid on the pitch."
And, with a nod even further to the future, Glenn reveals:
"Elliot Ward is just behind them."