Gannon hurts right shoulder against Chiefs
Backup Marques Tuiasosopo started the second half for the Raiders.
Gannon took two vicious hits from Shawn Barber in the second quarter, the second of which forced him to fumble with 23 seconds left. He slowly walked off the field holding his throwing shoulder.
The Raiders didn't immediately know the extent of the injury.
This story is from ESPN.com's automated news wire. Wire index
MORE NFL HEADLINES
- Belichick says Patriots 'followed every rule'
- NFL warns Seahawks about Lynch gesture
- NFLPA: Players shouldn't talk 'Deflategate'
- NFL conducts 40 interviews into 'Deflategate'