Coulombe was sent down to Triple-A Nashville prior to Friday's game, Jane Lee of MLB.com reports.
Coulombe has been unable to get into a groove this season, appearing in nine games and logging a 5.79 ERA and 1.50 WHIP. Over 9.1 innings, his K:BB sits at 7:5 and he recently gave up two earned runs off one hit and three walks during Wednesday's game against the White Sox. The left-hander will look to settle down and get back on track at the Triple-A level.