The pair continued to progress at a rapid rate last season as Ledley, an ever-present until January 19, won his first full England cap and Simon dazzled down the right flank and cemented his place in the Welsh team.
"We all saw Ledley's potential," said Glenn. "He had been played in midfield but I saw him as a defender, a good footballing defender and that's what he's proved to be.
"His consistent levels were very impressive for a young lad.
"He needed a rest but we couldn't give it to him because the squad was depleted but he's come through that, learned from that and he'll be better for it in the next two or three seasons.
"It's important we look after Ledley, Simon and make sure they are our long-term future."
Ledley was on the shortlist for the PFA Young Player of the Year while Simon either started, came on as substitute or was on the bench in all-but one of our 49 games last season.
"The good thing about Simon is that he's learning quickly," added boss Glenn.
"He's learning to adapt to play in the Premiership, he's learning from his international experience with Wales, learning from the coaching we're giving him and improving.
"He's played in some different positions are they are plenty of options to where he can play. I think that is bringing him on quickly as a player.
"He's a had a delightful season and, again, he's one over the next couple of seasons that will get better and better.
"He's signed a five-year contract, put pen to paper and committed himself to the club. That's good news for everyone."
Look out for more from Glenn looking back at last season and ahead to next term in the next few days...
Glenn Hoddle believes his young stars Ledley King and Simon Davies will get better and better.