Morse took himself out of his rehab appearance Monday night after seven innings. He could not throw the ball from left field to shortstop, and it worsened as the game went on. Nationals team doctors will re-examine Morse and further test the lat Morse first strained March 6. Morse will not play Thursday, as the Nationals had hoped. Johnson said the doctors are "concerned." When Morse returns, after more than a month of diagnoses and setbacks, they still don't know.