Coach Marvin Lewis said Sunday that Dunlap will miss at least four weeks with a sprained right knee. The Bengals play the Ravens on Sept. 10, which falls under the four-week time frame outlined by Lewis.
"It is what it is and now I have to do what I got to do to get back on the field," Dunlap said, according to the Cincinnati Enquirer. "They're not going to let me go back out there until I am fully prepared. It's one of those situations where you have to do a lot to get back out there and now I have to do it."
Dunlap was one of three Bengals starters injured in the team's preseason opener Friday night against the New York Jets. Travelle Wharton also suffered a knee injury, which a source told ESPN.com's John Clayton will cause the starting guard to miss the 2012 season.
Middle linebacker Rey Maualuga also left with a knee injury but walked around the sideline freely. After the game, he said he thought he would be all right.
Dunlap was injured in the first quarter of Friday's game after he clipped knees with Jets receiver Patrick Turner. He eventually walked slowly off the field with assistance. He had 9½ sacks as a rookie in 2010, but was limited by injuries last year and had only 4½ sacks.
The Bengals moved Dunlap into the starting spot at left end because five-year starter Robert Geathers was out with a knee injury. That means Jamaal Anderson, a 2007 first-round draft pick by the Falcons, will start Thursday's preseason game at Atlanta.
Information from ESPN NFC North blogger Jamison Hensley and The Associated Press was used in this report.