Lidge, 34, has not played during the 2011 Major League Baseball (MLB) season due to a rotator cuff strain in his throwing shoulder he suffered in spring training.
To make room for him, right-handed reliever Danys Baez, 2-4 with a 6.25 earned run average, was designated for assignment, the team said in a statement.
Lidge was 0-0 with a 3.52 ERA, two walks and 10 strikeouts in 7-2/3 innings during an eight-game rehabilitation stint between single-A Lakewood and double-A Reading.
Ryan Madson has excelled during Lidge's absence, collecting 15 saves in 16 opportunities for a Phillies team that owns the best record in MLB, leaving unclear how manager Charlie Manuel will handle closer duties.
Two-time All-Star Lidge has had his ups and downs since a spectacular 2008 campaign in which he saved all 41 chances in the regular season and was 7-for-7 in the postseason.
Lidge had 11 blown saves and had a 7.21 ERA in 2009, before posting 27 saves and a 2.96 ERA last season.
(Reporting by Larry Fine in New York, Editing by Frank Pingue)