That start would fall next Tuesday, when the Pirates travel to Minneapolis to open a three-game Interleague series.
Morton felt a bit of soreness in the hamstring while doing some pregame stretching and alerted the Pirates' staff to the minor discomfort. Though Morton didn't feel any pain while making his warmup pitches or while pitching a scoreless first inning, the Pirates opted to be cautious and remove the right-hander from the game after only 13 pitches.
"I came back after the first inning and from the feedback they got, they decided to take me out after the first inning," said Morton, one of three players the Pirates acquired in last week's trade that sent Nate McLouth to the Braves. "I was anxious coming back here to Atlanta and hopefully get some quality innings in. It's unfortunate."
Manager John Russell said afterward that the biggest concern was Morton's mobility and ability to cover first if needed. Morton was replaced by Jeff Karstens, the pitcher whose rotation spot Morton had just taken.
"Physically, other than the leg, I felt good," Morton said. "Mentally, I felt pretty comfortable. I'm really excited to be here. I really am. I'm just really excited."
Morton is listed as day-to-day and will be checked out by the medical staff again on Thursday. However, indications after Wednesday's game were that the injury was minimal enough that Morton should be ready to pitch next Tuesday.
"That was pretty electric stuff that first inning," Russell said. "I wish we could have seen more of it. He was pretty good. Hopefully we can get over this strain and he can continue to start."
Jenifer Langosch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.