The Green Bay Press-Gazette reported Packers Coach Mike McCarthy said after Sunday's loss to Dallas that there was blood in Harris' urine. During Monday's news conference McCarthy confirmed that Harris was undergoing further tests.
Harris left Sunday's game twice in the first quarter, once after colliding with linebacker A.J. Hawk downfield then later in the quarter after making a tackle. He did not return to the game after leaving for a second time.
Harris has seven tackles and five passes defensed in three games this season with Green Bay, his sixth with the Packers.