Triple-A Louisville placed Aguiar on the 7-day injured list July 21 due to an unspecified injury.
Aguiar is on the shelf for the second time this season, after Louisville previously deactivated him April 9 before reinstating him June 4. Through 11 starts at Triple-A this season, Aguiar has submitted a 6.23 ERA, 1.60 WHIP and 43:29 K:BB in 43.1 innings.