And now the leather-covered sphere came hurtling through the air, And Casey stood a-watching it in haughty grandeur there. Close by the sturdy batsman the ball unheeded sped— "That ain't my style," said Casey. "Strike one," the umpire said.
After all that buildup, the first pitch is finally on its way. The ESPN commentators usually just say, "and here's the pitch."
However, that's not quite dramatic enough in this context. Hence we get "the leather-covered sphere […] hurtling through the air."
Casey watches "in haughty grandeur" as the ball speeds by. He doesn't swing because he doesn't like the pitch ("That ain't my style"). However, the pitch is a strike.
Casey is described as "the sturdy batsman" in this stanza. This gives us the image of a strong, confident hitter. But he's also described as "haughty." This sounds negative, overconfident, and arrogant.
This is the first time in the poem we've seen a description of Casey that could be considered negative. Is our speaker starting to turn against Casey? Let's move on and find out…