In O'Brien the Royals add a still-solid power hitting prospect who gives the team some organizational depth. Kansas City finished the past season near the bottom of the majors in home runs (just 147, which was 27th overall) and O'Brien can provide some dingers in the future. His ability to play the outfield and possibly a little catcher and first base / designated hitter suggests he might eventually be a regular. He has talent (as a former 2nd-round draft pick).

The D-Backs already have solid depth in the outfield at the major league level, and so they move on here from O'Brien (who's a somewhat aging prospect who didn't quite pan out as expected for them). Baker isn't much of a prospect--he's a solid but unremarkable righty reliever--but he should provide the Royals another option out of the 'pen if he continues the progress he showed in the minors in 2016.

Don't draft O'Brien in anything but the deepest of keeper formats, but do keep him on the radar in case he gets called up by the Royals. He has an excellent power bat and may get catcher position eligibility in some leagues, which adds up to sleeper potential. That said, O'Brien doesn't have a clear-cut defensive position (which might limit his playing time) and his strikeout-to-walk ratio doesn't bode well for a high batting average or consistent game-to-game production. As for Lewis, it will be surprising if he makes a splash anytime soon in the majors or in fantasy.