Kansas City Chiefs running back Jamaal Charles' season is likely over. The Chiefs are placing him on injured reserve, as the effects of his 2015 ACL tear have lingered into this season, per several reports.

Charles now has to sit out at least eight weeks, making Week 17 the earliest he is eligible to return. It would appear extremely unlikely he'll be back this season.

Charles, whose 2015 torn ACL was the second of his NFL career, saw noted orthopedic surgeon Dr. James Andrews this week after he experienced swelling in his knee. It appears he will now need a second surgery on the knee.

Charles had returned to the Chiefs just a few weeks ago after spending the first few games of this season working back up to being able to get on the field. He'd been expected to assume a larger role in the offense after Kansas City's bye week, but he instead continued to play second fiddle to Spencer Ware as the knee was still bothering him. Charles then got onto the field for only two snaps for Kansas City's Week 7 win over the New Orleans Saints. He pulled up lame on a run and did not get back on the field the rest of the afternoon. He then sat out the entirety of Week 8.

With Charles presumably sidelined the rest of the way, the Chiefs worked out two familiar running backs to AFC fans.

Trent Richardson, of course, is a former first-rounder famously gone bust with the Browns, Colts, and Raiders. Ballard spent time with the Colts as well, but often missed time with injuries of his own. They also signed former Titans running back Bishop Sankey earlier in the day. With Ware in the concussion protocol this week, they are turning over all stones to find a backfield partner for Charcandrick West, who seems to be in line to assume most of the work if Ware can't get back on the field this week.