Hart, who is recovering from May 2010 right shoulder surgery, had been pitching in extended spring training games to try and rebuild his arm strength. The process, though, is not going well.
When the Pirates placed Hart on the 60-day disabled list during Spring Training, it was thought Hart would be ready to return to game action in June. Now, it's tough to decipher what the right-hander's timetable might be.
Hart last pitched with the Pirates in 2009, when he went 1-8 with a 6.92 ERA in 10 starts after being traded to Pittsburgh by the Cubs on July 30.
While Hart has hit a roadblock in his recovery, starter Ross Ohlendorf is taking steps forward in his progression back from a right shoulder strain. After throwing a number of bullpen sessions in Bradenton, Ohlendorf pitched in a simulated game on Friday without issue.
Ohlendorf, who has been on the DL since April 9, will continue pitching in Bradenton before eventually going out on a Minor League rehab assignment.