As Peter Flaherty arrived to watch batting practice at the Cape Cod League on Wednesday, he noticed a player that looked significantly bigger than everyone else on the field. The player? South Carolina slugger Ethan Petry. Flaherty hadn’t seen Petry play in person before, so he was taken by surprise at just how staggering he was. “He’s a monster, like he looks like, and I mean this complementary, he looks bigger than everyone else in little league but it’s the Cape League,” said Flaherty, a national writer/analyst for Baseball America. “It’s really, really impressive.” After playing in 61 game…