Glenn will run the rule over him at Brisbane Road and Roots Hall - a far cry, admittedly, from the Nou Camp - and explains:
"Oscar Garcia is with us for two games; he will play in the second half at Leyton Orient and probably the first half or the first hour at Southend on Tuesday.
"He was brought to our attention by one of the scouts that predominantly looks abroad for us, and I saw him play for the Catalan against Brazil before the World Cup, where I was impressed with him.
"This is an opportunity for us to have what they call in Europe an assessment for a couple of weeks.
"He joined up with us in Portugal, and as you can imagine for a player who has been at Barcelona, Valencia, and Espanol, he is completely happy with the ball at his feet, and technically very good.
"But what we have to decide, which is the most important thing, is 'is his game suited to the high tempo and strength of the Premiership?'
"He is certainly a very talented player technically."
The opening preseason game of the campaign is a testimonial for Len Cheesewright, who set Glenn on his path to stardom as a youngster when he brought him to Leyton Orient, and Glenn says:
"When I heard that he had been released from his duties at Leyton Orient I spoke to Len and said if I could help in any way I was happy to.
"He was very grateful that we made the offer of bringing the team over for the testimonial game, and it is the least I could do for someone who has helped me in my career.
"He is someone who has spent 40 years in the game at a level that is probably nowhere near as well paid as players are.
"These are the people who deserve to have testimonials, and if we can send Len away with a nest egg for the rest of his life it would be wonderful.
"It is not just me who owes him a debt; he has started off so many young boys in professional football, including the likes of Laurie Cunningham, Sol Campbell, and John Chiedozie.
"He has discovered many players and I hope some of the ex-players can be there tonight. "He worked with me as my chief scout at Watford and he found one or two interesting players for me there.
"He has had a great career, and he is certainly one of the faces of Sunday football on the touchlines; he is very important to the local community in this part of the world to any young boys who harbour thoughts of a career in football."
Len has said that Glenn is a an England manager in the making, and Glenn laughs:
"With that assessment, that is probably why they have retired him!"
But the notion may not be so far fetched for someone who has already been comfortable working at the highest level, and he adds:
"I am very happy to have been given this opportunity, and I have enough on my plate at the moment trying my very best for West Ham - those sort of thoughts are a long way away from me, and my ambitions are all about West Ham.
"It is typical of Len to say that about one of his ex-boys, though."
As for team news, Glenn will change everyone around at half time, with just a few absentees.
"Don is not playing," he says, "and when I knew Paolo wasn't joining us until the day after we got back from Portugal, I thought I would see him train for three or four days.
"But I fully expect Paolo to be playing at Southend on Tuesday night, and then the three England boys at Colchester."