The Pirates made the moves before Sunday's game at Washington.
''Charlie started feeling a level of discomfort a couple months ago,'' manager Clint Hurdle said. ''It's been manageable up until lately. Now it's starting to affect his performance.''
Morton is 5-12 with a 3.84 ERA and hasn't won since July 2. In his last two starts, he allowed 10 earned runs over eight innings in losses to San Diego and Washington.
Hurdle said right-hander Gerrit Cole, currently on the disabled list with a strained right lat, is scheduled to pitch Wednesday against Atlanta in what would have been Morton's next start.
This is Morel's third stint with the Pirates this year. He's appeared in nine games, batting .188 with three RBIs.