Atlanta optioned Fuentes to Triple-A Gwinnett on Thursday.
Fuentes was shaky in a spot start Wednesday versus the Nationals, striking out seven but permitting four earned runs on seven hits and a walk over three frames. The 20-year-old should get another opportunity in the Atlanta rotation later this summer, but for now he will continue to hone his craft at Gwinnett, where he's posted a 2.16 ERA and 20:6 K:BB in 16.2 innings.