No question- he’s declining. The deep ball certainly is the most noticeable decline- he underthew a LOT of deep balls last year. And if you’re running a power run game to draw defenders into the box, you will get a lot of big vertical strike opportunities.
But it maybe it’s his knee- his mechanics had to be all sorts of fucked up while he was playing on one leg- and as smart as he is, this possibility (even probability) can’t escape him as a source for his decline in play. There will be no shortage of subplots this coming season...