The Giants designated Borucki for assignment Sunday.
Borucki will lose his spot on the 40-man roster after he gave up at least one run in a third consecutive relief appearance during Saturday's 8-3 loss to the Rockies, bringing his ERA up to 4.94 over 23.2 innings on the season. The Giants will replace Borucki in the bullpen with right-hander Tristan Beck, who was recalled from Triple-A Sacramento in a corresponding move.