Ratliff has missed the first four games of the season with a high ankle sprain, an injury he suffered in the third preseason game.
Ratliff was limited in practices during the offseason with a foot injury but was cleared before the third preseason game in late August. After he suffered the ankle injury, there was a thought he could return in time for the season opener against the New York Giants.
"Jay is one of the top defensive players in this league," defensive end Marcus Spears said. "You miss a guy like that. Josh and Liss did a great job for us and they played great football and those guys stepped in and really did what they had to do to help us win.
"Getting Jay back is like getting three guys back in the nickel packages and the base packages, and teams actually gameplan for Jay Ratliff. So it will give other guys an opportunity to make more plays and have more success because he is in the game."
Last season, Ratliff was third on the team with 18 quarterback pressures and tied for third with six tackles for loss.
The Cowboys are seeking Ratliff's return at the right time, given they face a Ravens team that has the 13th-best rushing offense in the NFL at 117.6 yards per game. Baltimore running back Ray Rice is eighth in the league with 419 rushing yards.
According to ESPN Stats and Information, Rice is averaging 3.72 rushing yards per carry before first contact this season, tops among running backs with at least 40 carries.
"He worked very hard to get himself back in shape to play coming off the injury," Cowboys coach Jason Garrett said of Ratliff. "He's an outstanding football player, has been for a long time, and he makes a big impact on our defense and on our football team."