Source: Broken ribs sideline Packers' Ty Montgomery

GREEN BAY, Wis. -- The Green Bay Packers lost running back Ty Montgomery to broken ribs on their first possession Thursday night, a source told ESPN's Adam Schefter. There is not an immediate timetable for how much time Montgomery will miss.

NFL Network first reported Montgomery's injury.

No NFL running back had played more snaps this season than Montgomery and no Green Bay Packers skill position player had touched the ball more during the first three games in 2017.

Entering Week 4, Montgomery had played 23 more snaps than the second-most-used back, Dallas' Ezekiel Elliott, and had 39.6 percent of the Packers' touches, according to ESPN Stats & Information. The next-highest Packers player was receiver Randall Cobb with 10.7 percent.

Montgomery was off to a strong start with 28 yards on five carries in the first six plays from scrimmage. He came into the game with a wrist injury he sustained in Sunday's win over the Bengals.

It was 11 months ago against the Bears when Montgomery made his first start as a running back after converting from receiver. He had two big games against Chicago last season with 10 catches in the game at Lambeau Field and 162 yards rushing later in the season at Soldier Field.

Rookie fourth-round pick Jamaal Williams replaced Montgomery but left early in the second quarter because of a knee injury. Williams will not return.

A source told Schefter that Williams' knee is "stable."

With Williams sidelined, the Packers turned to Aaron Jones, who hadn't played from scrimmage entering the game.

Jones and fullback Aaron Ripkowski are the only remaining options for the running game.

In addition to losing two running backs, the team announced that linebacker Joe Thomas won't return to the game because of an ankle injury.