Former All Black Sonny Bill Williams injured his shoulder on Saturday playing for the Panasonic Wild Knights in Japanese club rugby.

Williams was taken to a hospital with his right arm in a sling after Panasonic beat the Kintetsu Liners 23-20.

Williams scored a try in the first minute but was taken out six minutes later after a collision with a Kintetsu player.

After having a MRI, Williams said on Twitter that the injury was a small tear, adding: “Hurt it today … results back nothing serious.”

Williams quit the All Blacks to pursue more lucrative opportunities in Japan and Australia.

He is reportedly earning $US1.2 million ($A1.17 million) for his 12-game stint in Japan, after which Williams is set to resume his rugby league career in Australia in the NRL.