The move is retroactive to Tuesday.
Neshek was sidelined on Opening Day, when the Phillies bullpen blew a lead. Manager Gabe Kapler said the reliever was dealing with a minor issue with a muscle in the right side of his back.
Tommy Hunter, another reliever the Phillies signed during the offseason to bolster their bullpen, opened the season on the DL because of a hamstring strain.
A two-time All-Star, Neshek was traded from the Phillies to the playoff-bound Colorado Rockies for three minor league players midway through last season, when he was an All-Star. In 62 1/3 innings between the two clubs, he turned in a 1.59 ERA. He then re-signed with Philadelphia for two years and $16.25 million in December.
Right-hander Yacksel Rios was recalled from Triple-A Lehigh Valley to take Neshek's place on the roster.