Horwitz (wrist) has gone 4-for-28 with five strikeouts on his rehab assignment split between Double-A Altoona and Triple-A Indianapolis.
Horwitz has been on assignment since April 27 and has needed extensive ramp-up time after missing all of spring training. He still hasn't found a rhythm at the plate, though he has struck out at a reasonable 16.7 percent clip. The Pirates need offensive help, but they may opt to let Horwitz start to hit better before activating him.