Ireland have something to prove after the lopsided loss and McClean was withering when asked about Liverpool boss Jurgen Klopp's dismissal of the Nations League as "the most senseless competition in the world".
Klopp is pleased a hectic schedule of seven matches in 23 days is now over but is unsure what the next fortnight will bring for his players.
It's so multi-cultural in London, there's people from all over the world, so it's just easy to go out and walk around and if I ever want to get back to Liverpool for a day or two, it doesn't take long to get to Euston for the train.
"All of the midfielders will be thinking that", he added. The players said it was a bit hard because people are coming pretty straight to you. But that's how it is.
The Reds are on course to challenge for major honours this year, having started the league season in tremendous form.
"I don't exactly know what you can win but there is some final next summer or something so that's it".
Liverpool are joint top of the league table with Chelsea and defending champions Manchester City after eight games played.
"He is a coach who demands a lot from his players, not only in matches but also on a daily basis in training", the Brazilian revealed. We have a lot of young talent, and even though I wasn't part of the World Cup squad, I can see everyone is developing really well now and if we can keep progressing over the years, there will be more success down the line.
Here at St George's Park on Tuesday, he was suggesting he could make a difference to the national team after three years without a competitive appearance.
"I've been through hard spells but I'm coming out of it a better player".
A Liverpudlian, who joined Everton as a schoolboy, Barkley's departure from Goodison Park, as he ran his contract down, was a drawn out and painful affair, but one he has put behind him.
"They are built for that, Jurgen (Klopp) is built for that".
"At the end we need to be happy - I need to be happy - that we didn't lose it because of the penalty".
'It should work, actually, at one point.
"When we win something, this city will explode - I'm sure - in a very positive way".
"It looks like we are really on a good way and the only thing I can guarantee is that we constantly develop".
"We have still time to do something special".