Collmenter cleared waivers and was outrighted to Triple-A Gwinnett on Thursday, Grant McAuley of 92.9 The Game reports.
Collmenter was designated for assignment by the Braves on Thursday.
Collmenter (0-2) gave up seven runs on six hits and a walk in the 10th inning of Wednesday's loss to the Pirates.
Collmenter will be available to pitch Friday's game against the Phillies, David O'Brien of the Atlanta Journal-Constitution reports.
Collmenter gave up two runs on three hits over two innings while striking out one in Friday's loss to the Pirates.
Collmenter got the start in Wednesday's Grapefruit League game against the Mets and allowed one run on four hits while striking out five over five innings.
Collmenter threw two shutout innings in Tuesday's Grapefruit League game against the Cardinals, allowing two hits.
Collmenter agreed to a one-year deal with the Braves on Monday, avoiding arbitration, David O'Brien of the Atlanta Journal-Constitution reports.
Collmenter pitched seven innings, allowing one run on six hits and no walks while striking out four in Thursday's no-decision against Philadelphia.
Collmenter (2-0) struck out eight and gave up two earned runs on four hits and three walks over five innings in a 7-3 victory over the Nationals on Saturday.