Source: Chung undergoing tests

FOXBOROUGH, Mass. -- Patriots second-year safety Patrick Chung, who was knocked out of Sunday’s win over the Chargers in the second quarter with a knee injury, is undergoing tests to determine its severity, according to a source familiar with the situation.

The source said it could be a couple of days before the extent of Chung's injury is known.

“Patrick is a pretty quick healer,” Patriots coach Bill Belichick said during his weekly interview on Boston sports radio station WEEI. “Hopefully this won’t keep him out long, if at all.”

Chung’s last play on Sunday came early in the second quarter when he was trailing receiver Richard Goodman on a 25-yard reception down the middle. At the end of the play, Chung could be seen with a noticeable limp.

That was the play on which Goodman gave up the ball after going to the ground, with Patriots safety James Sanders recovering.

Entering Sunday’s game, Chung ranked second on the team with 44 tackles and two blocked kicks on special teams.