CHICAGO -- Rehab assignments for Bobby Parnell and Vic Black will shift to Triple-A Las Vegas on Sunday, New York Mets manager Terry Collins said.

Parnell suffered a blown save Monday with Class A St. Lucie in his first minor-league action in three weeks. Originally working back from Tommy John surgery, Parnell became sidetracked because of forearm tightness. His velocity sat at 90-92 mph and he uncorked a pair of wild pitches Monday, but Collins said the reliever is ready to move his rehab assignment to Las Vegas after appearing once more for St. Lucie on Thursday.

Black, slowed by a mildly herniated disk in his neck that has affected a nerve, last pitched in a minor-league game on April 18. He was taken off a rehab assignment with his velocity sagging.

Black, who has resumed throwing off a mound at the Mets' complex in Port St. Lucie, also is scheduled to restart a rehab assignment on Sunday with Vegas.