This happened in parallel with Mamoru taking over the left side. At the same time, Park Han-Gyeol stepped back to the far post, letting his other two teammates occupy the six-yard box. It wasn't him being generous, but the Korean striker knew that people's attention was completely on Mamoru right now.
He could've insisted on going to that small box and diverted more attention, but that wouldn't have had a more positive effect than having the other two do that. Hell, if anything, with three strikers being concentrated in one spot, it would only lower their chance to get the ball there.
No, instead of doing that, it was better for him to act as Robin, letting the Batman of the team take over the whole section. Then, once he slipped from everyone's eyes, once his trusted companion had already wreaked enough havoc on the left side, that was when the Korean striker knew that he had to take action.
'Now!'
Thud!
