Spieth withdraws from Byron Nelson with wrist injury, status for PGA Championship uncertain

Jordan Spieth withdrew from the AT&T Byron Nelson due to an injury to his left wrist.
The injury requires rest and limited movement.
Spieth's injury will be assessed week to week and his status for the PGA Championship is uncertain.
Spieth experienced severe pain in his left wrist over the weekend.
Spieth needs a PGA Championship victory to complete the career grand slam.