Sendejo was placed in concussion protocol Sunday, Joel A. Erickson of The Indianapolis Star reports.
Sendejo racked up four tackles and a pass defended in Saturday's win over New England. However, his status is now in question for a Week 16 matchup against Arizona. If Sendejo is sidelined, it would leave a significant hole in the Colts' secondary, as he's played more than 80 percent of the team's defensive snaps in every game since Week 8.