I think he did that for Ono because if the putcher can do good with a catcher from 1st year then is the real deal. Also he had too many catchers, so needed to sacrifice one of them to write the plot of all of them.
Also, sensei has a really crude vision of baseball. Sometimes sports are not grateful to the players who put their lives in them. It happened with Tanba, Chris and all the players that can't play. :'(
If they still worship furuya even after this, I bet either they don't have eyes or brain.. And it seems like kataoka was giving sign to sawamura and all pitcher that he gonna give ace number to sawamura. (๑•ㅂ•)و✧
y'know what, i'm kinda glad that seidou lost this one. So that'll ring a wake up call for the coach especially that furuya, as he is now, is not a reliable starter.
The one where they lost against amahisa, seidou didn't completely lost face, because sawamura saved their ass. So the fact that furuya fucked it up was kinda let ago after furuya's declaration to be the best pitcher blabla. And during their practice matcher when furuya messed up or straining for a bit, he's immediately pulled and replaced by one of nori or kawada, and seidou won all those matches.
But this time, they go up against one of the semi-finalist of spring koshien, and furuya strains (again) himself in the middle of the game, but he's not pulled until they have 2 or 3 innings (sorry if it's not accurate, i didn't pay attention) left. And instead of nori who is more experienced and skilled, they replace it with kawada, and that's apparently not good enough to beat that team.
So yeah this makes it at least clearer (to me) that furuya's fuck ups are so severe it can cost an important match, and a player. Rip ono btw, istg i don't understand why tf sensei did this to you, you deserve better and so is chris senpai (i'll be forever salty about chris and sawamura has only formed battery one time).