Now that Vladimir Guerrero Jr. is in the majors, Austin Riley is arguably the game’s best third base prospect, though the Braves have been experimenting with Riley as a left fielder at Triple-A Gwinnett, The Athletic’s David O’Brien writes (subscription required). Riley has been receiving two starts per week in left field, opening the door for another potential midseason route to Atlanta’s 25-man roster.
While Josh Donaldson can’t be considered a total impediment to Riley at third base given Donaldson’s multiple injuries over the last two seasons, the Braves are surely hoping Donaldson will continue to be healthy and productive throughout 2019 (his only year under contract with the team). That leaves Riley without an obvious position at the MLB level this year, and his development at the plate has indicated that he is ready for a quick promotion. Heading into today’s action, Riley had a whopping .309/.386/.691 slash line and 14 homers through his first 153 Triple-A plate appearances.
Riley played exclusively at third base during his first four pro seasons, though he saw some time in the outfield during Spring Training, and has played a handful of games as a left fielder and first baseman at Gwinnett this year. First base isn’t really an option in Atlanta either with Freddie Freeman entrenched at the position, and of course, the Braves also have a pretty great left field option in Ronald Acuna Jr.
O’Brien mentions the possibility that Riley could up at third base this season after all, should the Braves decide to trade Donaldson if they fall out of the pennant race. If the Braves remain in the NL East hunt, however, another possibility would be to use Riley in left field while shifting Acuna to center field in place of the struggling Ender Inciarte. It has been a rough start to the year for Inciarte, who is hitting only .218/.295/.323 through 139 PA. It has been a few years since Inciarte has been anything more than a league-average hitter, though even more troubling is his defensive dropoff — his usually outstanding center field glove has produced a -4.3 UZR/150 and zero Defensive Runs Saved through 290 innings.