"That was just a player that was mentioned to us around August time as a possible loan signing in the January window," says Glenn, "but my feeling is that Portillo is going to be a huge player in Spanish and international football.
"It was just one name that came to us from an agent back in August - but a lot has changed since then as he is involved in the first team at Real Madrid now.
"The land lies differently now to how it did then and we haven't pursued it, because there would be little point.
"He is a top name and while we might not have heard too much of him in England yet we will do, that's for sure."
To back up his point, he gives the example of a recent goal by the 20 year-old in the Spanish Primera Liga.
"I noticed him last week come off the subs' bench and score the fourth goal against Valencia - and what a strike it was," says Glenn.
"It was wonderful play from Zidane to put Portillo through - and before the keeper could react he had hit the top corner of the net."