Morris pitched for 11 years in the majors with stops in St. Louis, San Francisco and Pittsburgh. A two-time National League All-Star he has a career record of 121-92 with a 3.98 ERA.
The Pirates recalled right-hander John Van Benschoten from Triple A Indianapolis to replace Morris on the roster. Van Benschoten was 4-0 with a 1.88 ERA. He will work out of the bullpen in long relief.
Lefty Phil Dumatrait will take Morris' spot in the starting rotation. Dumatrait is 0-1 this season with a 4.32 ERA.
The decision to release Morris means the Pirates will eat $11, 037, 283 in salary, including a $1 million buyout for 2009.
"The decision to acquire Matt Morris last July did not turn out to be a sound baseball judgment. Ownership's willingness to acquire Matt's contract (and all of the remaining salary instead of parting with a valued prospect), however, demonstrated ownership's commitment to fielding a championship team. I am confident that the investments that we are now making in this Club will be far more productive," said Pirates President Frank Coonley.