They do have Roldani Baldwin and Daniel Flores in the system, the latter being a great prospect, but he's only 16. Baldwin probably still has 2-3 years - he may get bumped up to high A this year - before he's ready and this has been his break out year.
It's Baldwins breakout year in regards to power. He's always hit for good contact and was projected to hit for good power. He doesn't strike out a lot but he never walks either. He's also not that great at Catcher. He and Pedro Castellanos are my new binkies now that Lin is on the big club and with Dubon and the Basabe's being traded.
Since June 4th, Roldani is hitting .392/.421/.637 in 107 PA with 4bb/13k, 10 doubles, 5 HRs.
Going further back to May 3rd and he's at .337/.366/.594 in 184 PA with 7bb/31, 16 doubles, 1 triple, 9 HRs.
He is currently in the midst of a 5 game hitting streak where he is 11/21 and has at least 2 hits in every game.
One interesting thing of note, he's always hit righties better than lefties outside of 2016. OPS vs R from 2014-2017: .820, .788, .646, 1.011
OPS vs L ,.436, .516, .809, .556
He also completely ditched 3b this year to concentrate solely on catching. FWIW, he was dreadful at 3b. Fielding percentage is a bad stat but .909 in 915 innings of work says something.