CINCINNATI -- The Reds optioned reliever J.J. Hoover to Triple-A Louisville on Wednesday, a few hours after his latest rough outing set a club record.

Hoover gave up five runs, including Javier Baez's grand slam, in the 15th inning of a 7-2 loss to the Chicago Cubs on Tuesday. It was the second grand slam allowed by Hoover this season and his sixth career, a club record. Hoover has allowed nine homers in 18 2/3 innings this season for a 13.50 ERA.

Keyvius Sampson was called up for his third stint in Cincinnati this season. He's 0-1 with a 7.71 ERA in four games.

The Reds' bullpen is by far the worst in the majors, allowing 61 homers in 78 games with a 6.08 ERA.