NEW ORLEANS — Drew Brees has been diagnosed with multiple rib fractures and a collapsed right lung, a person with knowledge of the situation said Monday.

The person spoke on condition of anonymity because the Saints have not announced specifics about Brees’ injury, which the 41-year-old quarterback said occurred on a heavy hit by San Francisco defensive lineman Kentavius Street in the second quarter of New Orleans 27-13 victory over the Niners on Sunday.

Brees’ injuries, which were first reported by ESPN, are expected to sideline the quarterback for multiple weeks.