Riley replaced Adonis Garcia in Saturday's split-squad game against the Marlins and went 2-for-2 with a double.
The No. 6 prospect in a deep Braves farm system, the 19-year-old Riley popped 20 home runs in Low-A Rome last year and has a huge ceiling if he can get his strikeouts under control. He'll head back to minor league camp when it begins next week and is years away from his major league debut, but he's made a good first impression on the big club.