Chris Paul's left knee injury could cause him to be sidelined for up to a month, a person with knowledge of the injury told USA TODAY Sports. The person spoke under the condition of anonymity because he was not authorized to speak publicly on the matter.

Paul collided knees with Memphis Grizzlies guard Mario Chalmers on Oct. 11, causing swelling that was bad enough to slow him down but not enough to keep him from playing three quarters in Houston's opening night 122-121 win over the Golden State Warriors on Tuesday.

Paul, who joined the Rockets via trade over the summer after spending six seasons with the Los Angeles Clippers, missed Houston's second game of the season on Wednesday night against Sacramento.

The New York Times was first to report the potential injury timetable.