Pirates starting pitcher Charlie Morton's May 14 return date against the Brewers will likely have to be pushed back, the right-hander told MLB.com Saturday. Morton, who was slated to make his season debut against Milwaukee, was flown back to Pittsburgh after he experienced tightness in his right shoulder during a rehab start with Triple-A Indianapolis Friday night.

"It's a setback for my readiness, sure -- assuming it will alter my schedule," Morton said. "I'm not expecting anything bad. A lot of it was precautionary, a bump in the road."

Morton is expected to undergo a full examination some time over the next few days.

He has posted a 1.69 ERA with 10 strikeouts over four rehab starts (16 innings) while working his way back from Tommy John surgery.