Harper was a late scratch from Tuesday's lineup versus the Mets due to a migraine, Mike Puma of the New York Post reports.
Worth noting is that Harper was inadvertently struck in the helmet by a Tomas Nido throw back to the pitcher in Monday's game, although he remained in that contest and it's not clear whether this is related to that. Consider him day-to-day for now. The Phillies will shift Alec Bohm over to first base to cover for Harper, while Whit Merrifield will enter the lineup at third base.