Luebke will head to Double-A San Antonio this week after three successful appearances at High-A Lake Elsinore.
The left-hander gave up one run and one hit in three one-inning appearances. Both came Friday, though Luebke needed just six pitches to get through the first inning.
"He threw a six-pitch inning and then had to finish in the pen, so that's encouraging," Padres interim manager Pat Murphy said Saturday. "He's going in the right direction."
Once one of the bright young pitchers in the National League, Luebke, 30, hasn't pitched in a Major League game since April 27, 2012. He had the first ligament-replacement surgery on May 23 of that year and then suffered a setback and needed a second procedure on Feb. 2, 2014.
Luebke is making his latest comeback as a reliever. He made 30 relief appearances for the Padres early in his Major League career.
Luebke has a 10-12 career record with a 3.25 ERA and 195 strikeouts in 188 1/3 innings that spanned 55 games.