Rookie Valdez day-to-day with left hamstring injury; O'Hearn activated

Pirates rookie Esmerlyn Valdez is considered day-to-day after leaving Friday's 12-2 loss to the Cubs with a left hamstring injury.

Valdez had homered in Wednesday's 4-2 win over the White Sox. The team activated first baseman Ryan O'Hearn to add depth ahead of the Cubs series.

Pittsburgh will need all hands on deck for the crucial home series against Milwaukee beginning September 15.