Sousuke keeping his injury from Rin, and most of all trying to keep it from everyone strikes me as him having actual hope of being healed and being able to continue swimming competitively in the future.
Specially when Kisumi sees him, the face he makes is one of anger and surprise - as if he doesn’t want him to know about it and tell anyone, i think a lot of it has to do with the fact that once you let the cat out of the bag it becomes more real. I do wonder if he told Gou anything, seeing as the last episode ended with both of them bumping into each other in the station.
The fact that he’s already swam, to prove his spot in the relay and in the relay itself, as well as in other demonstrations, it makes me think that the injury can’t be that bad just yet. Sousuke doesn’t seem like an irresponsible sportsman, and if he swims is because he still can, as long as he knows his boundaries and does it responsibly.
His time off and return to Samezuka might also have a lot to do with his therapy and taking a break, rather than being solely because of Rin. Though it may seem that his worry over Rin’s olympic future, his attitude towards Nitori’s health and contempt of Haru all seem to be related to swimming itself (making sure Rin does what he needs to to fulfill his dream, nitori not injuring himself, Haru only being deserving of a place in the olympic scenery if he’s serious about it)
I think the fact that he came back for Rin is even more deep and complex now, it’s as if he came to make sure himself that he’d be able to reach the top but Sousuke would be there to make sure what happened to him didn’t repeat again. He hasn’t been particularly insistent on the topic of Australia, and he seemed to understand most of rin’s short explanation of how he was saved by the Iwatobi kids.
I just really want them both to sit down and talk, will Rin feel guilty over man handling him and pushing him around? The entire scene is very intense, I mean, Sousuke’s eyes are closed when he’s being shoved - and though my initial theory was because he was counting to keep himself in control (he is a man of a strong and defined temper, certainly someone who wouldn’t allow anyone to push him around or rough handle him) but I think he was also hiding the pain the shove caused him, why he’s also very careful of the words he picks and why he waits to pry Rin back. It’s because it hurts and he’s keeping himself centered.
I think his distaste for Haru isn’t as mysterious anymore, it makes a lot more sense specially considering his words during the preview about who has the right to stand on ‘the’ stage. He doesn’t accept him because he knows he’s not being serious about something that’s cost him his shoulder; and giving his interactions with Nitori, it’s because he knows how hard the struggle is. Sousuke isn’t good with words, he doesn’t sugarcoat things but if you’re able to look into what he says, you can tell that his judgement of character is actually inclined towards being good enough, having potential, working hard and wanting to take swim seriously.
I wonder if his participation in the relay, has connecting with Rin again in mind, but it’s also about him seeking alternatives of why he swims, contemplating the fact that he may not be able to swim competitively, then why is he swimming. If he swims with his friends, and with Rin, will he find out the answer to his dilemma? His struggle now is about finding a whole new raison d’etre.
I also think it’s nice we got to see another side of Sousuke, the one who helps Nitori even though he doesn’t have to. The one who does it because he’s seen Nitori’s struggles to push his own limits, and maybe he sees a little bit of himself when he began to swim and the reason why he did it - how Rin took his time to teach him, was patient with him, how Rin made Sousuke want to swim. He can relate to that.
But he’s also doing it for Rin. His best friend, to help him have the team he wants, he now understand the significance of the relay to him, and if he can be a part of it and ensure that it has only the best people who want to be there and are going ot be there then he’ll do what he can.
Sousuke’s a complex and deep character, and i’m glad light is being shed in his motives, he’s not the douchebag that some people pointed him out to be.