The A's and Rangers also postponed their matchup slated for Thursday evening.
The Phillies have decided not to play their series finale against the Nationals on Thursday night, according to NBC Sports Philadelphia's Jim Salisbury.
Philadelphia reportedly made its decision during a team meeting on Thursday. The Nationals were not asked for their insight before the Phillies decision, per Salisbury.
Manager Joe Girardi addressed the possibility of a player strike on Wednesday.
"I would tell them to go with their heart," Girardi said. "Feelings are feelings. They're never right or wrong, they're just feelings. And you've got to go with what your heart tells you. I would support them whatever they did."
The NL East matchup is one of several games to be postponed on Thursday following the shooting of Kenosha, Wis. resident Jacob Blake. The A's voted not to play against the Rangers on Thursday, and the Twins voted not to face the Tigers, per The Athletics Ken Rosenthal.
At least four games will not be played Thursday, including the Red Sox-Blue Jays game, Twins-Tigers game and Rangers-Athletics game. Games between the Reds and Brewers, Mariners and Padres and Giants and Dodgers were postponed on Wednesday night.