The national team boss was in the stands for Albion's 2-0 defeat at Huddersfield Town.
Dunk has - so far - despite calls from fans and pundits, missed out on making the England squad.
It is thought that Southgate was watching the central defender, but while he didn't have a terrible game, he was far from the levels he has reached this season.
When asked if Hughton would say to Southgate that Dunk's performance wasn't representative of his season so far, he replied: "Yes I would. Dunky has been very good for us all season.
"Not only has he been good for us all season, but he is a player that has developed very well over the past few seasons. He has become more mature as a player and is very aware of the qualities he has got.
"All you can ask is an improvement over the years and that he has done.
"Everyone will make assessments of the games, but I don't think I can look at any player and say that one particularly stood out and had that good of a game. We weren't good enough, myself included - I am the manager of the team and we were all not good enough to get a result."