Callahan is considered day-to-day with a core muscle injury, Bridget Condon of NFL Network reports.
Callahan was a late addition to the Chargers' final Week 13 injury report with what was designated as a groin injury. However, he was ultimately ruled active and recorded an pick-six while playing 51 percent of the team's defensive snaps in Sunday's 27-20 loss to Las Vegas. While it's unclear if this groin issue is related to his new abdomen injury, Callahan may be in jeopardy of missing his first game of the season Week 14. It will be worth monitoring the cornerback's activity level in practice heading into this Sunday's tilt against Miami.