"I'm not that particularly disappointed I didn't play, to be honest," Upson told the B'ham Evening Mail.
"I don't think I would have wanted a cap as a kind of token gesture. My first cap, hopefully, will be a big thing for me, if that does happen.
"I didn't go down there with the expectation that I was going to play, which probably eased the fact when that's how it turned out.
"It was a big surprise that I got called up. I looked upon it as a great opportunity to learn and take whatever I could from the whole experience," he added.
"Being around a different set of players, the training, the way things were done in general - it's something a young man, in his progression, can only take good from."