The Cowboys have lost three defensive linemen in training camp, including end Tyrone Crawford for the season with a torn Achilles.
Ratliff has missed all the training camp practices and has been seen working with his teammates' footwork or hand placements on the sidelines.
"He is making progress," coach Jason Garrett said. "He's working very hard by himself and with some individual stuff that he's doing just technically to try and get himself back. He's working hard in the weight room. He's getting his rehab done with our trainers and he's making progress."
Ratliff started just six games last season because of ankle and groin injuries. He underwent sports hernia surgery in December, ending his season. He was limited during offseason workouts but was cleared to start practicing once training camp started.
But he suffered another injury while running sprints during a conditioning drill. Team officials said Ratliff looked good during the conditioning test and are confident he'll be a dominant force in 2013.
Garrett would like to see Ratliff play in at least one preseason game, much like some other players who are battling back from injuries.
"I think with all those guys, you want to see them play football in the preseason," Garrett said. "Each of those guys has a different timetable for doing that and we just got to see how they're doing that day-by-day, week-by-week. But you certainly want to get those guys ready to play against the Giants (in Week 1), and one of the real important things is to get them some preseason snaps. ... You certainly want to get them some snaps going against some live action before that opener."