AP

The Chiefs were having a good day in their first game at Arrowhead Stadium since a Thursday nightmare against the Broncos. And then the nightmare potentially returned.

Running back Jammal Charles has exited the contest against the Bears with an apparent right knee injury, which happened as he made a cut after getting a handoff near the Chicago end zone.

After the cut, the lower leg moved awkwardly before Charles was tackled.

In September 2011, Charles tore the ACL in his left knee. The extent of the damage to his right knee isn’t yet known.