Glen was included in the squad that travelled to Newcastle on Monday night, and is likely to feature regularly in travelling parties in the months to come as he integrates with the first team squad.
There has been some debate throughout his development about whether his best position was there or at centre half, where previous manager Harry Redknapp 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."
Glen is already way ahead of his age group and played for England U19s recently in Scandinavia.
"With Glen, the recent 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.
"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.
"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."