Chargers' McNeill carted off field

San Diego Chargers offensive tackle Marcus to-helmet hit on a block attempt.

Chargers running back Ryan Mathews took a toss to the left halfway through the first quarter and as McNeill tried to lead the way, his helmet made contact with the helmet of a Raiders' defender.

McNeill instantly collapsed to the ground. He eventually sat up and was talking to trainers, but he had to be carted off the field.

The Chargers later said he was diagnosed with a neck stinger.

His return to the game is doubtful.