The biggest injury news in the NFL during Week 9 comes out of Philadelphia, as Eagles quarterback Nick Foles suffered a broken collarbone on Sunday and will be out indefinitely. Also, Houston Texans running back Arian Foster is set for an MRI and San Francisco running back Marcus Lattimore is retiring.

After taking a hard sack from Houston Texans linebacker Whitney Mercilus, Nick Foles went to the sidelines at the end of the first quarter and stayed there for the remainder of the game. Originally believed to be an injury to his left (non-throwing) shoulder, ESPN NFL Insider Adam Schefter reported last night that Foles actually broke his collarbone and is out indefinitely. The third-year quarterback was 187-for-312 passing on the season for 2,163 yards, 13 touchdowns and 10 interceptions.

To put Foles' injury in perspective, Aaron Rodgers of the Green Bay Packers suffered a broken collarbone in 2013 against the Bears and missed seven weeks. Buffalo Bills running back C.J. Spiller also broke his collarbone a couple of weeks ago and still cannot practice for another six weeks. Depending on the severity of the fracture, Foles may be able to return sooner rather than later, but the team gave no timetable for his return. In the meantime, backup quarterback Mark Sanchez will take over the starting role.

Foles is just the beginning of concerning injury news throughout the league. Houston Texans running back Arian Foster, who has been dealing with a lingering hamstring issue, suffered a groin injury in the third quarter of Sunday's game against the Eagles and will undergo an MRI on Monday. The AFC's leading rusher (161 carries for 822 yards) was relieved by Alfred Blue, who has plenty of experience since he's filled in for Foster earlier this season. The 4-5 Texans could be in even more trouble if Foster's groin injury is significant because he's clearly the team's best player. Of the offense's 19 touchdowns, Foster has 10.

The San Francisco 49ers also received bad news concerning a running back of their own. Marcus Lattimore, the former South Carolina Gamecock who was drafted by the Niners in the fourth round of the 2013 NFL draft, will announce his retirement on Monday due to his persisting knee issues. Lattimore never played in a regular season NFL game ever since suffering a gruesome knee injury during his sophomore season at South Carolina. He's been rehabbing ever since and even managed to return to practice this year and go through contact drills, but he's frustrated with his lack of progress.

Prior to his 2012 injury, Lattimore was expected to be a first round pick in the NFL draft after amassing 2,677 rushing yards, 767 receiving yards and 41 total touchdowns in three seasons at South Carolina. Those impressive numbers include shortened campaigns in 2011 and 2012, during which he only played a total of 16 games. Now that Lattimore's retirement is imminent, it looks like San Francisco will view Carlos Hyde as Frank Gore's successor.

For more NFL injury news, check out ESPN's injury wire.