Looking for signs of players coming of age, how about Lucas Herbert?
Still only 20, he hit .410 for June (25/61) with only nine strikeouts (one homer, 11 RBIs). He's up to .276 with a hot start to July as well. Remember, he was Allard's catcher in high school, deemed the best catch-and-throw guy in the draft. Apparently, he's going to have offensive skills as well.
I recall that he homered in his first game as a pro, then tore his meniscus in the second game and was out for the season. Maybe he's finding his form.