"He's going to have to go on injured reserve," Brian Levy told the Green Bay Press-Gazette. Levy's firm Goal Line Football represents Jenkins.
The Packers made that move official on Wednesday, and they signed defensive end Kenny Pettway to take his place.
Jenkins was injured early in the fourth quarter of Green Bay's 30-21 loss to the Tampa Bay Buccaneers on Sunday. The fifth-year pro injured his chest muscle in an attempt to sack quarterback Brian Griese.
Veteran Kabeer Gbaja-Biamila is expected to start in place of Jenkins, though, Gbaja-Biamila has been used only as a pass-rushing specialist in recent seasons. The Packers also are expected to use Mike Montgomery and Jason Hunter more frequently in the rotation and possibly rookie Jeremy Thompson. Hunter, however, injured a hamstring against the Buccaneers and his status for Sunday's game against Atlanta is uncertain.
Jenkins is the second starter in as many weeks to be sidelined with a major injury. Cornerback Al Harris suffered a ruptured spleen Sept. 21 against the Dallas Cowboys and is out indefinitely.
Jenkins had 18 tackles (13 solo), 2 1/2 sacks and a team-high 10 quarterback hurries in four games this season.
Linebacker A.J. Hawk injured his groin on Sunday and may be out indefinitely, if not the rest of the season.
Pettway, 25, is a third-year pro from Grambling. The 6-foot-4, 248-pounder was a seventh-round pick of the Houston Texans in 2005, then spent the last two seasons with the Jaguars, where he recorded three sacks and 12 tackles in 17 games. He had one sack in 10 games last season, and two sacks in four preseason games.