Son Heung-min's authority has declined as he has become a "senior soldier nearing discharge"

From the perspective of the members retiring this time, Son Heung-min already looks like a senior soldier nearing discharge who is overly cautious even about falling leaves.
Even when participating in unit events or training, he seems to just be joking around with the youngest members, and it's simply getting on their nerves.
It would be better if he weren't there so they could have more influence, but they are frustrated because they have to serve under a senior until their own discharge date.